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<body style="display: inherit;"><div class="head"><p></p><h1 id="title" class="title">JSON-LD Syntax 1.0</h1><h2 id="subtitle">A Context-based JSON Serialization for Linking Data</h2><h2 id="unofficial-draft-26-april-2012">Unofficial Draft 26 April 2012</h2><dl><dt>Editors:</dt><dd><a href="http://manu.sporny.org/">Manu Sporny</a>, <a href="http://digitalbazaar.com/">Digital Bazaar</a></dd>
<dd>
<a href="http://greggkellogg.net/">
Gregg
Kellogg
</a>,
<a href="http://kellogg-assoc.com/">
Kellogg
Associates
</a>
</dd>
<dd>
<a href="http://www.markus-lanthaler.com/">
<ins class="diff-new">Markus
Lanthaler
</ins></a>,<a href="http://www.tugraz.at/"><ins class="diff-new">
Graz
University
of
Technology
</ins></a></dd>
<dt>
Authors:
</dt>
<dd>
<a href="http://digitalbazaar.com/">
Manu
Sporny
</a>,
<a href="http://digitalbazaar.com/">
Digital
Bazaar
</a>
</dd>
<dd>
<a href="http://digitalbazaar.com/">
Dave
Longley
</a>,
<a href="http://digitalbazaar.com/">
Digital
Bazaar
</a>
</dd>
<dd>
<a href="http://greggkellogg.net/">
Gregg
Kellogg
</a>,
<a href="http://kellogg-assoc.com/">
Kellogg
Associates
</a>
</dd>
<dd>
<a href="http://www.markus-lanthaler.com/">
Markus
Lanthaler
</a>,
<a href="http://www.tugraz.at/">
Graz
University
of
Technology
</a>
</dd>
<dd>
<a href="http://webbackplane.com/">
Mark
Birbeck
</a>,
<a href="http://webbackplane.com/">
Backplane
Ltd.
</a>
</dd>
</dl>
<p>
This
document
is
also
available
in
this
non-normative
format:
<a href="diff-20120318.html">
diff
to
previous
version
</a>.
</p>
<p class="copyright">
This
document
is
licensed
under
a
<a rel="license" href="http://creativecommons.org/licenses/by/3.0/" class="subfoot">
Creative
Commons
Attribution
3.0
License
</a>.
</p>
<hr />
</div>
<div id="abstract" class="introductory section">
<h2>
Abstract
</h2>
<p>
JSON
<del class="diff-old">[
RFC4627
]
</del>
has
proven
to
be
a
highly
useful
object
serialization
and
messaging
format.
In
an
attempt
to
harmonize
the
representation
of
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>
in
JSON,
this
specification
outlines
a
common
JSON
representation
format
for
expressing
directed
graphs;
mixing
both
Linked
Data
and
non-Linked
Data
in
a
single
document.
</p>
</div>
<div class="introductory section" id="sotd">
<h2>
Status
of
This
Document
</h2>
<p>
This
document
is
merely
a
public
working
draft
of
a
potential
specification.
It
has
no
official
standing
of
any
kind
and
does
not
represent
the
support
or
consensus
of
any
standards
organisation.
</p>
<p>
This
document
is
an
experimental
work
in
progress.
</p>
</div>
<div id="toc" class="section">
<h2 class="introductory">
Table
of
Contents
</h2>
<ul class="toc">
<li class="tocline">
<a href="#introduction" class="tocxref">
<span class="secno">
1.
</span>
Introduction
</a>
<ul class="toc">
<li class="tocline">
<a href="#how-to-read-this-document" class="tocxref">
<span class="secno">
1.1
</span>
How
to
Read
this
Document
</a>
</li>
<li class="tocline">
<a href="#syntax-tokens-and-keywords" class="tocxref">
<span class="secno">
1.2
</span>
Syntax
Tokens
and
Keywords
</a>
</li>
<li class="tocline">
<a href="#contributing" class="tocxref">
<span class="secno">
1.3
</span>
Contributing
</a>
</li>
</ul>
</li>
<li class="tocline">
<a href="#design-goals-and-rationale" class="tocxref">
<span class="secno">
2.
</span>
Design
<ins class="diff-new">Goals
and
Rationale
</ins>
</a>
</li>
<li class="tocline">
<a href="#basic-concepts" class="tocxref">
<span class="secno">
<del class="diff-old">2.1
</del>
<ins class="diff-chg">3.
</ins>
</span>
<del class="diff-old">Goals
and
Rationale
</del>
<ins class="diff-chg">Basic
Concepts
</ins>
</a>
<ul class="toc">
<li class="tocline">
<a href="#linking-data" class="tocxref">
<span class="secno">
<del class="diff-old">2.2
</del>
<ins class="diff-chg">3.1
</ins>
</span>
Linking
Data
</a>
<ul class="toc">
<li class="tocline">
<a href="#the-context" class="tocxref">
<span class="secno">
<del class="diff-old">2.2.1
</del>
<ins class="diff-chg">3.1.1
</ins>
</span>
The
Context
</a>
</li>
<li class="tocline">
<a href="#from-json-to-json-ld" class="tocxref">
<span class="secno">
<del class="diff-old">2.2.2
</del>
<ins class="diff-chg">3.1.2
</ins>
</span>
From
JSON
to
JSON-LD
</a>
</li>
</ul>
</li>
<del class="diff-old">3.
Basic
Concepts
</del>
<li class="tocline">
<a href="#iris" class="tocxref">
<span class="secno">
<del class="diff-old">3.1
</del>
<ins class="diff-chg">3.2
</ins>
</span>
IRIs
</a>
</li>
<li class="tocline">
<a href="#identifying-the-subject" class="tocxref">
<span class="secno">
<del class="diff-old">3.2
</del>
<ins class="diff-chg">3.3
</ins>
</span>
Identifying
the
Subject
</a>
</li>
<li class="tocline">
<a href="#specifying-the-type" class="tocxref">
<span class="secno">
<del class="diff-old">3.3
</del>
<ins class="diff-chg">3.4
</ins>
</span>
Specifying
the
Type
</a>
</li>
<li class="tocline">
<del class="diff-old">3.4
Strings
</del>
<a href="#string-internationalization" class="tocxref">
<span class="secno">
3.5
</span>
String
Internationalization
</a>
</li>
<li class="tocline">
<a href="#sets-and-lists" class="tocxref">
<span class="secno">
3.6
</span>
<del class="diff-old">Typed
Values
3.7
Multiple
Objects
for
a
Single
Property
3.8
Multiple
Values
for
a
Single
Property
3.9
</del>
<ins class="diff-chg">Sets
and
</ins>
Lists
</a>
</li>
</ul>
</li>
<li class="tocline">
<a href="#advanced-concepts" class="tocxref">
<span class="secno">
4.
</span>
Advanced
Concepts
</a>
<ul class="toc">
<li class="tocline">
<a href="#typed-values" class="tocxref">
<span class="secno">
4.1
</span>
<del class="diff-old">Compact
IRIs
</del>
<ins class="diff-chg">Typed
Values
</ins>
</a>
</li>
<li class="tocline">
<a href="#compact-iris" class="tocxref">
<span class="secno">
4.2
</span>
<del class="diff-old">External
Contexts
</del>
<ins class="diff-chg">Compact
IRIs
</ins>
</a>
</li>
<li class="tocline">
<a href="#external-contexts" class="tocxref">
<span class="secno">
4.3
</span>
<del class="diff-old">Referencing
</del>
<ins class="diff-chg">External
</ins>
Contexts
<del class="diff-old">from
JSON
Documents
</del>
</a>
</li>
<li class="tocline">
<a href="#referencing-contexts-from-json-documents" class="tocxref">
<span class="secno">
4.4
</span>
<del class="diff-old">Default
Language
</del>
<ins class="diff-chg">Referencing
Contexts
from
JSON
Documents
</ins>
</a>
</li>
<li class="tocline">
<a href="#expanded-term-definition" class="tocxref">
<span class="secno">
4.5
</span>
Expanded
Term
Definition
</a>
</li>
<li class="tocline">
<del class="diff-old">4.6
Automatic
Typing
</del>
<a href="#type-coercion" class="tocxref">
<span class="secno">
<del class="diff-old">4.7
</del>
<ins class="diff-chg">4.6
</ins>
</span>
Type
Coercion
</a>
</li>
<li class="tocline">
<a href="#iri-expansion-within-a-context" class="tocxref">
<span class="secno">
<del class="diff-old">4.8
</del>
<ins class="diff-chg">4.7
</ins>
</span>
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
Expansion
Within
a
Context
</a>
</li>
<li class="tocline">
<a href="#embedding" class="tocxref">
<span class="secno">
<del class="diff-old">4.9
</del>
<ins class="diff-chg">4.8
</ins>
</span>
Embedding
</a>
</li>
<li class="tocline">
<a href="#named-graphs" class="tocxref">
<span class="secno">
<ins class="diff-new">4.9
</ins></span><ins class="diff-new">
Named
Graphs
</ins></a></li><li class="tocline">
<a href="#identifying-unlabeled-nodes" class="tocxref">
<span class="secno">
4.10
</span>
Identifying
Unlabeled
Nodes
</a>
</li>
<li class="tocline">
<a href="#aliasing-keywords" class="tocxref">
<span class="secno">
4.11
</span>
Aliasing
Keywords
</a>
</li>
<li class="tocline">
<a href="#expansion" class="tocxref">
<span class="secno">
4.12
</span>
Expansion
</a>
</li>
<li class="tocline">
<a href="#compaction" class="tocxref">
<span class="secno">
4.13
</span>
Compaction
</a>
</li>
<li class="tocline">
<a href="#framing" class="tocxref">
<span class="secno">
4.14
</span>
Framing
</a>
<ul class="toc">
<li class="tocline">
<a href="#framing-operators" class="tocxref">
<span class="secno">
<del class="diff-old">4.15
</del>
<ins class="diff-chg">4.14.1
</ins>
</span>
<del class="diff-old">Normalization
</del>
<ins class="diff-chg">Framing
Operators
</ins>
</a>
</li>
</ul>
</li>
</ul>
</li>
<li class="tocline">
<a href="#markup-examples" class="tocxref">
<span class="secno">
A.
</span>
Markup
Examples
</a>
<ul class="toc">
<li class="tocline">
<a href="#turtle" class="tocxref">
<span class="secno">
A.1
</span>
Turtle
</a>
<ul class="toc">
<li class="tocline">
<a href="#prefix-definitions" class="tocxref">
<span class="secno">
A.1.1
</span>
Prefix
definitions
</a>
</li>
<li class="tocline">
<a href="#embedding-1" class="tocxref">
<span class="secno">
A.1.2
</span>
Embedding
</a>
</li>
<li class="tocline">
<a href="#lists" class="tocxref">
<span class="secno">
A.1.3
</span>
Lists
</a>
</li>
</ul>
</li>
<li class="tocline">
<a href="#rdfa" class="tocxref">
<span class="secno">
A.2
</span>
RDFa
</a>
</li>
<li class="tocline">
<a href="#microformats" class="tocxref">
<span class="secno">
A.3
</span>
Microformats
</a>
</li>
<li class="tocline">
<a href="#microdata" class="tocxref">
<span class="secno">
A.4
</span>
Microdata
</a>
</li>
</ul>
</li>
<li class="tocline">
<a href="#linked-data" class="tocxref">
<span class="secno">
B.
</span>
Linked
Data
</a>
</li>
<li class="tocline">
<a href="#mashing-up-vocabularies" class="tocxref">
<span class="secno">
C.
</span>
Mashing
Up
Vocabularies
</a>
</li>
<li class="tocline">
<a href="#iana-considerations" class="tocxref">
<span class="secno">
D.
</span>
IANA
Considerations
</a>
</li>
<li class="tocline">
<a href="#acknowledgements" class="tocxref">
<span class="secno">
E.
</span>
Acknowledgements
</a>
</li>
<li class="tocline">
<a href="#references" class="tocxref">
<span class="secno">
F.
</span>
References
</a>
<ul class="toc">
<li class="tocline">
<a href="#normative-references" class="tocxref">
<span class="secno">
F.1
</span>
Normative
references
</a>
</li>
<li class="tocline">
<a href="#informative-references" class="tocxref">
<span class="secno">
F.2
</span>
Informative
references
</a>
</li>
</ul>
</li>
</ul>
</div>
<div class="informative section" id="introduction">
<h2>
<span class="secno">
1.
</span>
Introduction
</h2>
<p>
<em>
This
section
is
non-normative.
</em>
</p>
<p>
JSON,
as
specified
in
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-RFC4627">
RFC4627
</a>
</cite>
],
is
a
simple
language
for
representing
data
on
the
Web.
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>
is
a
technique
for
creating
a
graph
of
interlinked
data
across
different
documents
or
Web
sites.
Data
entities
are
described
using
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
s,
which
are
typically
dereferencable
and
thus
may
be
used
to
find
more
information
about
an
entity,
creating
a
&quot;Web
of
Knowledge&quot;.
JSON-LD
is
intended
to
be
a
simple
publishing
method
for
expressing
not
only
Linked
Data
in
JSON,
but
also
for
adding
semantics
to
existing
JSON.
</p>
<p>
JSON-LD
is
designed
as
a
lightweight
syntax
that
can
be
used
to
express
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>.
It
is
primarily
intended
to
be
a
way
to
use
Linked
Data
in
Javascript
and
other
Web-based
programming
environments.
It
is
also
useful
when
building
interoperable
Web
services
and
when
storing
Linked
Data
in
JSON-based
document
storage
engines.
It
is
practical
and
designed
to
be
as
simple
as
possible,
utilizing
the
large
number
of
JSON
parsers
and
libraries
available
today.
</p>
<p>
The
syntax
does
not
necessarily
require
applications
to
change
their
JSON,
but
allows
one
to
easily
add
meaning
by
simply
adding
or
referencing
a
context.
The
syntax
is
designed
to
not
disturb
already
deployed
systems
running
on
JSON,
but
provide
a
smooth
upgrade
path
from
JSON
to
JSON-LD
with
added
semantics.
Finally,
the
format
is
intended
to
be
easy
to
parse,
efficient
to
generate,
and
only
requires
a
very
small
memory
footprint
in
order
to
operate.
</p>
<div id="how-to-read-this-document" class="section">
<h3>
<span class="secno">
1.1
</span>
How
to
Read
this
Document
</h3>
<p>
This
document
is
a
detailed
specification
for
a
serialization
of
Linked
Data
in
JSON.
The
document
is
primarily
intended
for
the
following
audiences:
</p>
<ul>
<li>
Software
developers
that
want
to
encode
Linked
Data
in
a
way
that
is
cross-language
compatible
via
JSON.
</li>
<li>
Software
developers
that
want
to
understand
the
design
decisions
and
language
syntax
for
JSON-LD.
</li>
<li>
Software
developers
that
want
to
implement
processors
and
APIs
for
JSON-LD.
</li>
</ul>
<p>
This
specification
does
not
describe
the
programming
interfaces
for
the
JSON-LD
Syntax.
The
specification
that
describes
the
programming
interfaces
for
JSON-LD
documents
is
the
JSON-LD
Application
Programming
Interface
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-JSON-LD-API">
JSON-LD-API
</a>
</cite>
].
</p>
<p>
To
understand
the
basics
in
this
specification
you
must
first
be
familiar
with
JSON,
which
is
detailed
in
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-RFC4627">
RFC4627
</a>
</cite>
].
To
understand
the
API
and
how
it
is
intended
to
operate
in
a
programming
environment,
it
is
useful
to
have
working
knowledge
of
the
JavaScript
programming
language
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-ECMA-262">
ECMA-262
</a>
</cite>
]
and
WebIDL
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-WEBIDL">
WEBIDL
</a>
</cite>
].
</p>
<p>
JSON
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-RFC4627">
RFC4627
</a>
</cite>
]
defines
several
terms
which
are
used
throughout
this
document:
</p>
<dl>
<dt>
<dfn title="json_object" id="dfn-json_object">
JSON
<del class="diff-old">Object
</del>
<ins class="diff-chg">object
</ins>
</dfn>
</dt>
<dd>
An
object
structure
is
represented
as
a
pair
of
curly
brackets
surrounding
zero
or
more
name/value
pairs
(or
members).
A
name
is
a
<a class="tref internalDFN" title="string" href="#dfn-string">
string
</a>.
A
single
colon
comes
after
each
name,
separating
the
name
from
the
value.
A
single
comma
separates
a
value
from
a
following
name.
The
names
within
an
object
<em class="rfc2119" title="should">
should
</em>
be
unique.
</dd>
<dt>
<dfn title="array" id="dfn-array">
array
</dfn>
</dt>
<dd>
An
array
is
an
ordered
collection
of
values.
An
array
structure
is
represented
as
square
brackets
surrounding
zero
or
more
values
(or
elements).
Elements
are
separated
by
commas.
Within
JSON-LD,
array
order
is
not
preserved
by
default,
unless
specific
markup
is
provided
(see
<a href="#sets-and-lists">
<ins class="diff-chg">Sets
and
</ins>
Lists
</a>
).
This
is
because
the
basic
data
model
of
JSON-LD
is
a
<a class="tref internalDFN" title="linked_data_graph" href="#dfn-linked_data_graph">
linked
data
graph
</a>,
which
is
inherently
unordered.
</dd>
<dt>
<dfn title="string" id="dfn-string">
string
</dfn>
</dt>
<dd>
A
string
is
a
sequence
of
zero
or
more
Unicode
characters,
wrapped
in
double
quotes,
using
backslash
escapes.
A
character
is
represented
as
a
single
character
string.
</dd>
<dt>
<dfn title="number" id="dfn-number">
number
</dfn>
</dt>
<dd>
A
number
is
is
similar
to
that
used
in
most
programming
languages,
except
that
the
octal
and
hexadecimal
formats
are
not
used
and
that
leading
zeros
are
not
allowed.
</dd>
<dt>
<dfn title="true" id="dfn-true">
true
</dfn>
and
<dfn title="false" id="dfn-false">
false
</dfn>
</dt>
<dd>
Values
that
are
used
to
express
one
of
two
possible
boolean
states.
</dd>
<dt>
<dfn title="null" id="dfn-null">
null
</dfn>
</dt>
<dd>
<del class="diff-old">The
use
</del>
<ins class="diff-chg">Unless
otherwise
specified,
a
JSON-LD
processor
</ins><em class="rfc2119" title="must"><ins class="diff-chg">
must
</ins></em><ins class="diff-chg">
act
as
if
a
key-value
pair
in
the
body
</ins>
of
<ins class="diff-new">a
JSON-LD
document
was
never
declared
when
</ins>
the
<ins class="diff-new">value
equals
</ins><em><ins class="diff-new">
null
</ins></em>.<ins class="diff-new">
If
</ins><code><ins class="diff-new">
@value
</ins></code>,<code><ins class="diff-new">
@list
</ins></code>,<ins class="diff-new">
or
</ins><code><ins class="diff-new">
@set
</ins></code><ins class="diff-new">
is
set
to
</ins>
<em>
null
</em>
<del class="diff-old">value
</del>
<ins class="diff-chg">in
expanded
form,
then
the
entire
JSON
object
</ins>
is
<del class="diff-old">undefined
</del>
<ins class="diff-chg">ignored.
If
</ins><code><ins class="diff-chg">
@context
</ins></code><ins class="diff-chg">
is
set
to
</ins><em><ins class="diff-chg">
null
</ins></em>,<ins class="diff-chg">
the
</ins><a class="tref internalDFN" title="active_context" href="#dfn-active_context"><ins class="diff-chg">
active
context
</ins></a><ins class="diff-chg">
is
reset
and
when
used
</ins>
within
<del class="diff-old">JSON-LD.
</del>
<ins class="diff-chg">a
</ins><a class="tref internalDFN" title="context" href="#dfn-context"><ins class="diff-chg">
context
</ins></a>,<ins class="diff-chg">
it
removes
any
definition
associated
with
the
key,
unless
otherwise
specified.
</ins></dd><dt><dfn title="subject_definition" id="dfn-subject_definition"><ins class="diff-chg">
subject
definition
</ins></dfn></dt><dd><ins class="diff-chg">
A
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-chg">
JSON
object
</ins></a><ins class="diff-chg">
used
to
represent
a
</ins><a class="tref internalDFN" title="subject" href="#dfn-subject"><ins class="diff-chg">
subject
</ins></a><ins class="diff-chg">
and
one
or
more
properties
of
that
subject.
A
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-chg">
JSON
object
</ins></a><ins class="diff-chg">
is
a
subject
definition
if
it
does
not
contain
they
keys
</ins><code><ins class="diff-chg">
@value
</ins></code>,<code><ins class="diff-chg">
@list
</ins></code><ins class="diff-chg">
or
</ins><code><ins class="diff-chg">
@set
</ins></code><ins class="diff-chg">
and
it
has
one
or
more
keys
other
than
</ins><code><ins class="diff-chg">
@id
</ins></code>.</dd><dt><dfn title="subject_reference" id="dfn-subject_reference"><ins class="diff-chg">
subject
reference
</ins></dfn></dt><dd><ins class="diff-chg">
A
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-chg">
JSON
object
</ins></a><ins class="diff-chg">
used
to
reference
a
subject
having
only
the
</ins><code><ins class="diff-chg">
@id
</ins></code><ins class="diff-chg">
key.
</ins>
</dd>
</dl>
<p>
</p>
</div>
<div id="syntax-tokens-and-keywords" class="section">
<h3>
<span class="secno">
1.2
</span>
Syntax
Tokens
and
Keywords
</h3>
<p>
JSON-LD
specifies
a
number
of
syntax
tokens
and
<dfn title="keyword" id="dfn-keyword">
keywords
</dfn>
that
are
using
in
all
algorithms
described
in
this
section:
</p>
<dl>
<dt>
<code>
@context
</code>
</dt>
<dd>
Used
to
define
the
short-hand
names
that
are
used
throughout
a
JSON-LD
document.
These
short-hand
names
are
called
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
and
help
developers
<ins class="diff-new">to
</ins>
express
specific
identifiers
in
a
compact
manner.
The
<code>
@context
</code>
keyword
is
described
in
detail
in
the
section
titled
<a href="#the-context">
The
Context
</a>.
</dd>
<dt>
<code>
<ins class="diff-new">@graph
</ins></code></dt><dd><ins class="diff-new">
Used
to
explicitly
express
a
</ins><a class="tref internalDFN" title="linked_data_graph" href="#dfn-linked_data_graph"><ins class="diff-new">
linked
data
graph
</ins></a>.</dd><dt><code>
@id
</code>
</dt>
<dd>
Used
to
uniquely
identify
things
that
are
being
described
in
the
document.
This
keyword
is
described
in
the
section
titled
<a href="#identifying-the-subject">
Identifying
the
Subject
</a>.
</dd>
<dt>
<code>
@value
</code>
</dt>
<dd>
Used
to
specify
the
data
that
is
associated
with
a
particular
<a class="tref internalDFN" title="property" href="#dfn-property">
property
</a>
in
the
graph.
This
keyword
is
described
in
the
sections
titled
<a href="#string-internationalization">
String
Internationalization
</a>
and
<a href="#typed-values">
Typed
Values
</a>.
</dd>
<dt>
<code>
@language
</code>
</dt>
<dd>
Used
to
specify
the
native
language
for
a
particular
<del class="diff-old">value.
</del>
<ins class="diff-chg">value
or
the
default
language
of
a
JSON-LD
document.
</ins>
This
keyword
is
described
in
the
section
titled
<a href="#string-internationalization">
String
Internationalization
</a>.
</dd>
<dt>
<code>
@type
</code>
</dt>
<dd>
Used
to
set
the
data
type
of
a
<a class="tref internalDFN" title="subject" href="#dfn-subject">
subject
</a>
or
<a class="tref internalDFN" title="typed_value" href="#dfn-typed_value">
typed
value
</a>.
This
keyword
is
described
in
the
section
titled
<a href="#typed-values">
Typed
Values
</a>.
</dd>
<dt>
<code>
@container
</code>
</dt>
<dd>
Used
to
set
the
container
of
a
particular
value.
This
keyword
is
described
in
the
section
titled
<a href="#sets-and-lists">
<ins class="diff-chg">Sets
and
</ins>
Lists
</a>.
</dd>
<dt>
<code>
@list
</code>
</dt>
<dd>
Used
to
express
an
ordered
set
of
data.
This
keyword
is
described
in
the
section
titled
<a href="#sets-and-lists">
<ins class="diff-chg">Sets
and
Lists
</ins></a>.</dd><dt><code><ins class="diff-chg">
@set
</ins></code></dt><dd><ins class="diff-chg">
Used
to
express
an
unordered
set
of
data.
This
keyword
is
described
in
the
section
titled
</ins><a href="#sets-and-lists"><ins class="diff-chg">
Sets
and
</ins>
Lists
</a>.
</dd>
<dt>
<code>:
</code>
</dt>
<dd>
The
separator
for
JSON
keys
and
values
that
use
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
IRIs
</a>.
</dd>
</dl>
<p>
For
the
avoidance
of
doubt,
all
keys,
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keywords
</a>,
and
values
in
JSON-LD
are
case-sensitive.
</p>
</div>
<div id="contributing" class="section">
<h3>
<span class="secno">
1.3
</span>
Contributing
</h3>
<p>
There
are
a
number
of
ways
that
one
may
participate
in
the
development
of
this
specification:
</p>
<ul>
<li>
Technical
discussion
typically
occurs
on
the
public
mailing
list:
<a href="http://lists.w3.org/Archives/Public/public-linked-json/">
public-linked-json@w3.org
</a>
</li>
<li>
<a href="http://json-ld.org/minutes/">
Public
teleconferences
</a>
are
held
every
week
on
Tuesdays
at
1500
UTC.
</li>
<li>
Specification
bugs
and
issues
should
be
reported
in
the
<a href="https://github.com/json-ld/json-ld.org/issues">
issue
tracker
</a>.
</li>
<li>
<a href="https://github.com/json-ld/json-ld.org/tree/main/spec">
Source
code
</a>
for
the
specification
can
be
found
on
Github.
</li>
<li>
The
<a href="http://webchat.freenode.net/?channels=json-ld">
#json-ld
</a>
IRC
channel
is
available
for
real-time
discussion
on
irc.freenode.net.
</li>
</ul>
</div>
</div>
<div class="informative section" id="design-goals-and-rationale">
<h2>
<span class="secno">
2.
</span>
Design
<ins class="diff-new">Goals
and
Rationale
</ins>
</h2>
<p>
<em>
This
section
is
non-normative.
</em>
</p>
<p>
<del class="diff-old">The
following
section
outlines
the
design
goals
and
rationale
behind
the
JSON-LD
markup
language.
2.1
Goals
and
Rationale
</del>
A
number
of
design
considerations
were
explored
during
the
creation
of
this
markup
language:
</p>
<dl>
<dt>
Simplicity
</dt>
<dd>
Developers
need
only
know
JSON
and
two
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keywords
</a>
(
<code>
@context
</code>
and
<code>
@id
</code>
)
to
use
the
basic
functionality
in
JSON-LD.
No
extra
processors
or
software
libraries
are
necessary
to
use
JSON-LD
in
its
most
basic
form.
The
language
attempts
to
ensure
that
developers
have
an
easy
learning
curve.
</dd>
<dt>
Compatibility
</dt>
<dd>
The
JSON-LD
markup
must
be
100%
compatible
with
JSON.
This
ensures
that
all
of
the
standard
JSON
libraries
work
seamlessly
with
JSON-LD
documents.
</dd>
<dt>
Expressiveness
</dt>
<dd>
The
syntax
must
be
able
to
express
directed
graphs,
which
have
been
proven
to
be
able
to
<del class="diff-old">simply
</del>
express
almost
every
real
world
data
model.
</dd>
<dt>
Terseness
</dt>
<dd>
The
JSON-LD
syntax
must
be
very
terse
and
human
readable,
requiring
as
little
effort
as
possible
from
the
developer.
</dd>
<dt>
Zero
Edits,
most
of
the
time
</dt>
<dd>
JSON-LD
provides
a
mechanism
that
allows
developers
to
specify
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
in
a
way
that
is
out-of-band.
This
allows
organizations
that
have
already
deployed
large
JSON-based
infrastructure
to
add
meaning
to
their
JSON
documents
in
a
way
that
is
not
disruptive
to
their
day-to-day
operations
and
is
transparent
to
their
current
customers.
At
times,
mapping
JSON
to
a
graph
representation
can
become
difficult.
In
these
instances,
rather
than
having
JSON-LD
support
esoteric
markup,
we
chose
not
to
support
the
use
case
and
support
a
simplified
syntax
instead.
So,
while
Zero
Edits
is
a
goal,
it
is
not
always
possible
without
adding
great
complexity
to
the
language.
</dd>
<dt>
One-pass
Processing
</dt>
<dd>
JSON-LD
supports
one-pass
processing,
which
results
in
a
very
small
memory
footprint
when
processing
documents.
For
example,
to
expand
a
JSON-LD
document
from
a
compacted
form,
only
one
pass
is
required
over
the
data.
</dd>
</dl>
</div>
<div id="basic-concepts" class="section">
<h2>
<span class="secno">
<ins class="diff-new">3.
</ins></span><ins class="diff-new">
Basic
Concepts
</ins></h2><p><ins class="diff-new">
JSON-LD
is
designed
to
ensure
that
</ins><a class="tref internalDFN" title="linked_data" href="#dfn-linked_data"><ins class="diff-new">
Linked
Data
</ins></a><ins class="diff-new">
concepts
can
be
marked
up
in
a
way
that
is
simple
to
understand
and
create
by
Web
authors.
In
many
cases,
regular
JSON
markup
can
become
Linked
Data
with
the
simple
addition
of
a
</ins><a class="tref internalDFN" title="context" href="#dfn-context"><ins class="diff-new">
context
</ins></a>.<ins class="diff-new">
As
more
JSON-LD
features
are
used,
more
semantics
are
added
to
the
JSON
markup.
</ins></p>
<div id="linking-data" class="section">
<h3>
<span class="secno">
<del class="diff-old">2.2
</del>
<ins class="diff-chg">3.1
</ins>
</span>
Linking
Data
</h3>
<p>
An
Internationalized
Resource
Identifier
(
<dfn title="iri" id="dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</dfn>
),
as
described
in
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-RFC3987">
RFC3987
</a>
</cite>
],
is
a
mechanism
for
representing
unique
identifiers
on
the
<del class="diff-old">web.
</del>
<ins class="diff-chg">Web.
</ins>
In
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>,
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
is
commonly
used
for
expressing
a
<a class="tref internalDFN" title="subject" href="#dfn-subject">
subject
</a>,
a
<a class="tref internalDFN" title="property" href="#dfn-property">
property
</a>
or
an
<a class="tref internalDFN" title="object" href="#dfn-object">
object
</a>.
</p>
<p>
JSON-LD
defines
a
mechanism
to
map
JSON
terms,
i.e.,
keys
and
values,
to
IRIs.
This
does
not
mean
that
JSON-LD
requires
every
key
or
value
to
be
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>,
but
rather
ensures
that
keys
and
values
can
be
mapped
to
IRIs
if
the
developer
desires
to
transform
their
data
into
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>.
There
are
a
few
techniques
that
can
ensure
that
developers
will
generate
good
Linked
Data
for
the
Web.
JSON-LD
formalizes
those
techniques.
</p>
<p>
We
will
be
using
the
following
JSON
markup
as
the
example
for
the
rest
of
this
section:
</p>
<del class="diff-old">{
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
</ins>
}
</pre>
<div id="the-context" class="section">
<h4>
<span class="secno">
<del class="diff-old">2.2.1
</del>
<ins class="diff-chg">3.1.1
</ins>
</span>
The
Context
</h4>
<p>
In
JSON-LD,
a
<dfn title="context" id="dfn-context">
context
</dfn>
is
used
to
map
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s,
i.e.,
<del class="diff-old">keys
</del>
<ins class="diff-chg">properties
</ins>
with
associated
values
in
an
JSON
document,
to
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
s.
A
<dfn title="term" id="dfn-term">
term
</dfn>
is
a
short
word
that
<del class="diff-old">may
be
expanded
</del>
<ins class="diff-chg">expands
</ins>
to
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
<del class="diff-old">A
</del>
<a class="tref internalDFN" title="term" href="#dfn-term">
<del class="diff-old">term
</del>
<ins class="diff-chg">Term
</ins>
</a>
<del class="diff-old">must
</del>
<ins class="diff-chg">s
</ins><em class="rfc2119" title="may"><ins class="diff-chg">
may
</ins>
</em>
<del class="diff-old">have
the
lexical
form
of
NCName
</del>
<ins class="diff-chg">be
defined
as
any
valid
JSON
</ins><a class="tref internalDFN" title="string" href="#dfn-string"><ins class="diff-chg">
string
</ins>
</a>
<del class="diff-old">(see
[
XML-NAMES
</del>
<ins class="diff-chg">other
than
a
JSON-LD
</ins><a class="tref internalDFN" title="keyword" href="#dfn-keyword"><ins class="diff-chg">
keyword
</ins></a>.<ins class="diff-chg">
To
avoid
forward-compatibility
issues,
</ins><a class="tref internalDFN" title="term" href="#dfn-term"><ins class="diff-chg">
term
</ins>
</a>
<del class="diff-old">]),
compact
IRI
,
absolute
IRI
,
or
be
</del>
<ins class="diff-chg">s
starting
with
</ins>
an
<del class="diff-old">empty
string.
</del>
<code>
<ins class="diff-chg">@
</ins></code><ins class="diff-chg">
character
</ins><em class="rfc2119" title="should not"><ins class="diff-chg">
should
not
</ins></em><ins class="diff-chg">
be
used
as
they
might
be
used
as
</ins><a class="tref internalDFN" title="keyword" href="#dfn-keyword"><ins class="diff-chg">
keywords
</ins></a><ins class="diff-chg">
in
future
versions
of
JSON-LD.
</ins>
</p>
<p>
The
Web
uses
<a class="tref internalDFN" title="iri" href="#dfn-iri">
IRIs
</a>
for
unambiguous
identification.
The
idea
is
that
these
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
mean
something
that
may
be
of
use
to
other
developers
and
that
it
is
useful
to
give
them
an
unambiguous
identifier.
That
is,
it
is
useful
for
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
to
expand
to
IRIs
so
that
developers
don't
accidentally
step
on
each
other's
<dfn title="vocabulary" id="dfn-vocabulary">
vocabulary
</dfn>
<ins class="diff-new">terms.
Furthermore,
developers,
and
machines,
are
able
to
use
this
</ins><a class="tref internalDFN" title="iri" href="#dfn-iri"><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr>
</a>
<ins class="diff-new">(by
plugging
it
directly
into
a
web
browser,
for
instance)
to
go
to
the
term
and
get
a
definition
of
what
the
term
means.
Much
like
we
can
use
</ins><a href="http://wordnet.princeton.edu/"><ins class="diff-new">
WordNet
</ins></a><ins class="diff-new">
today
to
see
the
definition
of
words
in
the
English
language.
Developers
and
machines
need
the
same
sort
of
definition
of
</ins>
terms.
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<ins class="diff-new">IRIs
</ins></a><ins class="diff-new">
provide
a
way
to
ensure
that
these
terms
are
unambiguous.
</ins>
For
example,
the
term
<code>
name
</code>
may
map
directly
to
the
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
<code>
http://xmlns.com/foaf/0.1/name
</code>.
This
allows
JSON-LD
documents
to
be
constructed
using
the
common
JSON
practice
of
simple
name/value
pairs
while
ensuring
that
the
data
is
useful
outside
of
the
page,
API
or
database
in
which
it
resides.
The
value
of
a
term
mapping
<em class="rfc2119" title="must">
must
</em>
be
either;
1)
a
simple
string
with
the
lexical
form
of
an
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
<del class="diff-old">or,
</del>
<ins class="diff-chg">or
</ins>
2)
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
<ins class="diff-new">compact
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr></a>,<ins class="diff-new">
or
3)
</ins>
an
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
containing
an
<code>
@id
</code>,
<code>
@type
</code>,
<code>
@language
</code>,
or
<code>
@container
</code>
<del class="diff-old">keyword.
</del>
<ins class="diff-chg">keyword
(all
other
keywords
are
ignored
by
a
JSON-LD
processor).
</ins>
</p>
<p>
These
Linked
Data
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
are
typically
collected
in
a
context
document
that
would
look
something
like
this:
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;depiction&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/depiction&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
    &quot;homepage&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
  }
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;depiction&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/depiction&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
    &quot;homepage&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
  }
</ins>
}
</pre>
<p>
<del class="diff-old">This
</del>
<ins class="diff-chg">Assuming
that
this
</ins>
context
document
can
<del class="diff-old">then
</del>
be
<del class="diff-old">used
in
an
</del>
<ins class="diff-chg">retrieved
at
</ins><code><ins class="diff-chg">
http://json-ld.org/contexts/person
</ins></code>,<ins class="diff-chg">
it
can
be
referenced
from
a
</ins>
JSON-LD
document
by
adding
a
single
line.
The
JSON
markup
<del class="diff-old">as
</del>
shown
in
the
previous
section
could
be
changed
as
<del class="diff-old">follows
to
link
to
the
context
document:
</del>
<ins class="diff-chg">follows:
</ins>
</p>
<del class="diff-old">{

  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
</del>
<pre class="example">{
  <span class="diff">&quot;@context&quot;: &quot;http://json-ld.org/contexts/person&quot;,</span>
<ins class="diff-chg">  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
</ins>
}
</pre>
<p>
The
additions
above
transform
the
previous
JSON
document
into
a
JSON
document
with
added
semantics
because
the
<code>
@context
</code>
specifies
how
the
<strong>
name
</strong>,
<strong>
homepage
</strong>,
and
<strong>
depiction
</strong>
terms
map
to
<a class="tref internalDFN" title="iri" href="#dfn-iri">
IRIs
</a>.
Mapping
those
keys
to
IRIs
gives
the
data
global
context.
If
two
developers
use
the
same
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
to
describe
a
property,
they
are
more
than
likely
expressing
the
same
concept.
This
allows
both
developers
to
re-use
each
others
data
without
having
to
agree
to
how
their
data
will
interoperate
on
a
site-by-site
basis.
Contexts
may
also
contain
type
information
for
certain
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
as
well
as
other
processing
instructions
for
the
JSON-LD
processor.
</p>
<p>
Contexts
<em class="rfc2119" title="may">
may
</em>
be
specified
in-line.
This
ensures
that
JSON-LD
documents
can
be
processed
when
a
JSON-LD
processor
does
not
have
access
to
the
Web.
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;depiction&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/depiction&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
    &quot;homepage&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
  },
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
</del>
<pre class="example">{
  <span class="diff">&quot;@context&quot;:
<ins class="diff-chg">  {
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;depiction&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/depiction&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
    &quot;homepage&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
  },</span>
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
</ins>
}
</pre>
<p>
Contexts
<em class="rfc2119" title="may">
may
</em>
be
used
at
any
time
a
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
is
defined.
A
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
<em class="rfc2119" title="may">
may
</em>
specify
multiple
contexts,
using
an
<a class="tref internalDFN" title="array" href="#dfn-array">
array
</a>,
which
is
processed
in
<del class="diff-old">array-order.
</del>
<ins class="diff-chg">order.
</ins>
This
is
useful
when
an
author
would
like
to
use
an
existing
context
and
add
application-specific
terms
to
the
existing
context.
Duplicate
context
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
<em class="rfc2119" title="must">
must
</em>
be
overridden
using
a
last-defined-overrides
mechanism.
</p>
<p class="note">
<ins class="diff-new">If
a
</ins><a class="tref internalDFN" title="term" href="#dfn-term"><ins class="diff-new">
term
</ins></a><ins class="diff-new">
is
re-defined
within
a
context,
all
previous
rules
associated
with
the
previous
definition
are
removed.
A
</ins><a class="tref internalDFN" title="term" href="#dfn-term"><ins class="diff-new">
term
</ins></a><ins class="diff-new">
defined
in
a
previous
context
</ins><em class="rfc2119" title="must"><ins class="diff-new">
must
</ins></em><ins class="diff-new">
be
removed,
if
it
is
re-defined
to
</ins><code><ins class="diff-new">
null
</ins></code>.</p>
<p>
The
set
of
contexts
defined
within
a
specific
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
<del class="diff-old">Object
</del>
<ins class="diff-chg">object
</ins>
</a>
are
referred
to
as
<dfn title="local_context" id="dfn-local_context">
local
context
</dfn>
s.
<ins class="diff-new">Setting
the
context
to
</ins><code><ins class="diff-new">
null
</ins></code><ins class="diff-new">
effectively
sets
the
</ins><a class="tref internalDFN" title="local_context" href="#dfn-local_context"><ins class="diff-new">
local
context
</ins></a><ins class="diff-new">
to
it's
initial
state.
</ins>
The
<dfn title="active_context" id="dfn-active_context">
active
context
</dfn>
refers
to
the
accumulation
of
<a class="tref internalDFN" title="local_context" href="#dfn-local_context">
local
context
</a>
s
that
are
in
scope
at
a
specific
point
within
the
document.
The
following
example
specifies
an
external
context
and
then
layers
a
local
context
on
top
of
the
external
context:
</p>
<del class="diff-old">{
  &quot;@context&quot;: [
    &quot;http://json-ld.org/contexts/person&quot;,
    {
      &quot;pic&quot;: &quot;http://xmlns.com/foaf/0.1/depiction&quot;
    }
  ],
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,

</del>
<pre class="example">{
  <span class="diff">&quot;@context&quot;: [
<ins class="diff-chg">    &quot;http://json-ld.org/contexts/person&quot;,
    {
      &quot;pic&quot;: &quot;http://xmlns.com/foaf/0.1/depiction&quot;
    }
  ],</span>
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
</ins>  <span class="diff">&quot;pic&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;</span>
}
</pre>
<del class="diff-old">JSON-LD
uses
a
special
type
of
machine-readable
document
called
a
vocabulary
to
define
term
s
that
are
then
used
to
describe
concepts
and
&quot;things&quot;
in
the
world.
Typically,
these
vocabulary
documents
have
prefix
es
associated
with
them
and
contain
a
number
of
term
declarations.
Prefix
es
are
helpful
when
a
developer
wants
to
mix
multiple
vocabularies
together
in
a
context
,
but
does
not
want
to
go
to
the
trouble
of
defining
every
single
term
in
every
single
vocabulary.
Some
vocabularies
may
have
dozens
of
terms
defined.
If
a
developer
wants
to
use
3-4
different
vocabularies
,
the
number
of
terms
that
would
have
to
be
declared
in
a
single
context
could
become
quite
large.
To
reduce
the
number
of
different
terms
that
must
be
defined,
JSON-LD
also
allows
prefixes
to
be
used
to
compact
IRIs
.
For
example,
the
IRI
http://xmlns.com/foaf/0.1/
specifies
a
vocabulary
which
may
be
represented
using
the
foaf
prefix
.
The
foaf
vocabulary
contains
a
term
called
name
.
If
you
join
the
foaf
prefix
with
the
name
suffix,
you
can
build
a
compact
IRI
that
will
expand
out
into
an
absolute
IRI
for
the
http://xmlns.com/foaf/0.1/name
vocabulary
term.
That
is,
the
compact
IRI
(or
short-form),
is
foaf:name
and
the
expanded-form
is
http://xmlns.com/foaf/0.1/name
.
This
vocabulary
term
is
used
to
specify
a
person's
name.
Developers,
and
machines,
are
able
to
use
this
IRI
(by
plugging
it
directly
into
a
web
browser,
for
instance)
to
go
to
the
term
and
get
a
definition
of
what
the
term
means.
Much
like
we
can
use
WordNet
today
to
see
the
definition
of
words
in
the
English
language.
Developers
and
machines
need
the
same
sort
of
definition
of
terms.
IRIs
provide
a
way
to
ensure
that
these
terms
are
unambiguous.
The
context
provides
a
collection
of
vocabulary
term
s
that
can
be
used
to
expand
JSON
keys
and
values
into
IRIs
.
</del>
<p class="note">
To
ensure
the
best
possible
performance,
it
is
a
best
practice
to
put
the
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
definition
at
the
top
of
the
JSON-LD
document.
If
it
isn't
listed
first,
processors
have
to
save
each
key-value
pair
until
the
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
is
processed.
This
creates
a
memory
and
complexity
burden
for
one-pass
processors.
</p>
</div>
<div id="from-json-to-json-ld" class="section">
<h4>
<span class="secno">
<del class="diff-old">2.2.2
</del>
<ins class="diff-chg">3.1.2
</ins>
</span>
From
JSON
to
JSON-LD
</h4>
<p>
If
a
set
of
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
such
as,
<strong>
name
</strong>,
<strong>
homepage
</strong>,
and
<strong>
depiction
</strong>,
are
defined
in
a
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>,
and
that
context
is
used
to
resolve
the
names
in
JSON
objects,
machines
are
able
to
automatically
expand
the
terms
to
something
meaningful
and
unambiguous,
like
this:
</p>
<del class="diff-old">{
  &quot;&quot;: &quot;Manu Sporny&quot;,
  &quot;&quot;: &quot;http://manu.sporny.org&quot;
  &quot;&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;<span class="diff">http://xmlns.com/foaf/0.1/name</span>&quot;: &quot;Manu Sporny&quot;,
  &quot;<span class="diff">http://xmlns.com/foaf/0.1/homepage</span>&quot;: &quot;http://manu.sporny.org&quot;
  &quot;<span class="diff">http://xmlns.com/foaf/0.1/depiction</span>&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
</ins>
}
</pre>
<p>
Doing
this
allows
JSON
to
be
unambiguously
machine-readable
without
requiring
developers
to
drastically
change
their
workflow.
</p>
<p class="note">
The
example
above
does
not
use
the
<code>
@id
</code>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>
to
set
the
<a class="tref internalDFN" title="subject" href="#dfn-subject">
subject
</a>
of
the
node
being
described
above.
This
type
of
node
is
called
an
<dfn title="unlabeled_node" id="dfn-unlabeled_node">
unlabeled
node
</dfn>
and
is
considered
to
be
a
weaker
form
of
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>.
It
is
advised
that
all
nodes
described
in
JSON-LD
are
given
unique
identifiers
via
the
<code>
@id
</code>
keyword
unless
the
data
is
not
intended
to
be
linked
to
from
other
data
sets.
</p>
<del class="diff-old">3.
Basic
Concepts
</del>
<p>
<del class="diff-old">JSON-LD
is
designed
to
ensure
that
Linked
Data
</del>
<ins class="diff-chg">A
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-chg">
JSON
object
</ins>
</a>
<del class="diff-old">concepts
can
be
marked
up
in
a
way
that
is
simple
</del>
<ins class="diff-chg">used
</ins>
to
<del class="diff-old">understand
and
create
by
Web
authors.
In
many
cases,
regular
JSON
markup
can
become
Linked
Data
with
the
simple
addition
of
</del>
<ins class="diff-chg">define
property
values
is
called
</ins>
a
<del class="diff-old">context
</del>
<a class="tref internalDFN" title="subject_definition" href="#dfn-subject_definition">
<ins class="diff-chg">subject
definition
</ins>
</a>.
<del class="diff-old">As
more
JSON-LD
features
are
used,
more
semantics
</del>
<a class="tref internalDFN" title="subject_definition" href="#dfn-subject_definition">
<ins class="diff-chg">Subject
definitions
</ins></a><ins class="diff-chg">
do
not
require
a
</ins><code><ins class="diff-chg">
@id
</ins></code>,<ins class="diff-chg">
in
which
case
they
</ins>
are
<del class="diff-old">added
</del>
<ins class="diff-chg">considered
</ins>
to
<del class="diff-old">the
JSON
markup.
</del>
<ins class="diff-chg">be
an
</ins><a class="tref internalDFN" title="unlabeled_node" href="#dfn-unlabeled_node"><ins class="diff-chg">
unlabeled
node
</ins></a>.
</p>
</div>
</div>
<div id="iris" class="section">
<h3>
<span class="secno">
<del class="diff-old">3.1
</del>
<ins class="diff-chg">3.2
</ins>
</span>
IRIs
</h3>
<p>
Expressing
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
s
are
fundamental
to
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>
as
that
is
how
most
<a class="tref internalDFN" title="subject" href="#dfn-subject">
subject
</a>
s,
all
<a class="tref internalDFN" title="property" href="#dfn-property">
properties
</a>
and
many
<a class="tref internalDFN" title="object" href="#dfn-object">
object
</a>
s
are
identified.
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
s
can
be
expressed
in
a
variety
of
different
ways
in
JSON-LD.
</p>
<ol>
<li>
Except
within
a
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
definition,
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
in
the
key
position
in
a
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
that
have
a
mapping
to
an
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
or
another
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
in
the
<a class="tref internalDFN" title="active_context" href="#dfn-active_context">
active
context
</a>
are
expanded
to
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
by
JSON-LD
processors.
</li>
<li>
An
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
is
generated
for
the
<a class="tref internalDFN" title="string" href="#dfn-string">
string
</a>
value
specified
using
<code>
@id
</code>
or
<code>
@type
</code>.
</li>
<li>
An
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
is
generated
for
the
<a class="tref internalDFN" title="string" href="#dfn-string">
string
</a>
value
of
any
key
for
which
there
are
<a class="tref internalDFN" title="coercion" href="#dfn-coercion">
coercion
</a>
rules
in
effect
that
identify
the
value
as
an
<code>
@id
</code>.
</li>
</ol>
<p>
IRIs
may
be
represented
as
an
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>,
a
<a class="tref internalDFN" title="relative_iri" href="#dfn-relative_iri">
relative
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>,
a
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>,
or
a
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
</p>
<p>
An
<dfn title="absolute_iri" id="dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</dfn>
is
defined
in
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-RFC3987">
RFC3987
</a>
</cite>
]
containing
a
<em>
scheme
</em>
along
with
<em>
path
</em>
and
optional
<em>
query
</em>
and
<em>
fragment
</em>
segments.
A
<dfn title="relative_iri" id="dfn-relative_iri">
relative
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</dfn>
is
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
that
is
relative
some
other
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
;
in
the
case
of
JSON-LD
this
is
the
base
location
of
the
document.
</p>
<p>
IRIs
can
be
expressed
directly
in
the
key
position
like
so:
</p>
<del class="diff-old">{
...
  &quot;&quot;: &quot;Manu Sporny&quot;,
...
</del>
<pre class="example">{
<ins class="diff-chg">...
  &quot;<span class="diff">http://xmlns.com/foaf/0.1/name</span>&quot;: &quot;Manu Sporny&quot;,
...
</ins>
}
</pre>
<p>
In
the
example
above,
the
key
<code>
http://xmlns.com/foaf/0.1/name
</code>
is
interpreted
as
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>,
as
opposed
to
being
interpreted
as
a
string.
</p>
<p>
Term
expansion
occurs
for
IRIs
if
the
value
matches
a
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
defined
within
the
<a class="tref internalDFN" title="active_context" href="#dfn-active_context">
active
context
</a>:
</p>
<del class="diff-old">{
  &quot;&quot;:
  {
    &quot;&quot;
...
  },
  &quot;&quot;: &quot;Manu Sporny&quot;,
...
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;<span class="diff">@context</span>&quot;:
  {
    &quot;<span class="diff">name</span>&quot;: &quot;<span class="diff">http://xmlns.com/foaf/0.1/name</span>&quot;
...
  },
  &quot;<span class="diff">name</span>&quot;: &quot;Manu Sporny&quot;,
...
</ins>
}
</pre>
<p>
<a class="tref internalDFN" title="prefix" href="#dfn-prefix">
Prefix
</a>
es
are
expanded
when
the
form
of
the
value
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
represented
as
is
<code>
prefix:suffix
</code>,
and
the
prefix
matches
a
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
defined
within
the
<a class="tref internalDFN" title="active_context" href="#dfn-active_context">
active
context
</a>:
</p>
<del class="diff-old">{
  &quot;&quot;:
  {
    &quot;&quot;
...
  },
  &quot;&quot;: &quot;Manu Sporny&quot;,
...
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;<span class="diff">@context</span>&quot;:
  {
    &quot;<span class="diff">foaf</span>&quot;: &quot;<span class="diff">http://xmlns.com/foaf/0.1/</span>&quot;
...
  },
  &quot;<span class="diff">foaf:name</span>&quot;: &quot;Manu Sporny&quot;,
...
</ins>
}
</pre>
<p>
<a class="tref internalDFN" title="term" href="#dfn-term">
Term
</a>
s
are
case
sensitive,
and
<em class="rfc2119" title="must">
must
</em>
be
matched
using
a
case-sensitive
comparison.
</p>
<p>
Keys
that
do
not
expand
to
an
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
are
ignored.
</p>
<del class="diff-old">It
is
not
determined
if
processing
proceeds
into
values
of
undefined
keys.
If
so,
this
would
result
in
a
graph
which
is
not
embedded
.
</del>
<p>
<code>
foaf:name
</code>
above
will
automatically
expand
out
to
the
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
<code>
http://xmlns.com/foaf/0.1/name
</code>.
See
<a href="#compact-iris">
Compact
IRIs
</a>
for
more
details.
</p>
<p>
An
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
is
generated
when
a
value
is
associated
with
a
key
using
the
<code>
@id
</code>
keyword:
</p>
<del class="diff-old">{
...
  &quot;homepage&quot;: { &quot;&quot;: &quot;http://manu.sporny.org&quot; }
...
</del>
<pre class="example">{
<ins class="diff-chg">...
  &quot;homepage&quot;: { &quot;<span class="diff">@id</span>&quot;: &quot;http://manu.sporny.org&quot; }
...
</ins>
}
</pre>
<p class="note">
Specifying
a
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
<del class="diff-old">Object
</del>
<ins class="diff-chg">object
</ins>
</a>
with
an
<code>
@id
</code>
key
is
used
to
identify
that
object
using
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
This
facility
<em class="rfc2119" title="may">
may
</em>
also
be
used
to
link
a
<a class="tref internalDFN" title="subject" href="#dfn-subject">
subject
</a>
with
an
<a class="tref internalDFN" title="object" href="#dfn-object">
object
</a>
using
a
mechanism
called
<a class="tref internalDFN" title="embedding" href="#dfn-embedding">
embedding
</a>,
which
is
covered
in
the
section
titled
<a href="#embedding">
Embedding
</a>.
</p>
<p>
If
type
<a class="tref internalDFN" title="coercion" href="#dfn-coercion">
coercion
</a>
rules
are
specified
in
the
<code>
@context
</code>
for
a
particular
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
or
property
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>,
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
is
generated:
</p>
<del class="diff-old">
  &quot;@context&quot;:
  {
    ...
    &quot;homepage&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    }
    ...
  }
...
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
...
</del>
<pre class="example">{<span class="diff">
<ins class="diff-chg">  &quot;@context&quot;:
  {
    ...
    &quot;homepage&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    }
    ...
  }</span>
...
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
...
</ins>
}
</pre>
<p>
Even
though
the
value
<code>
http://manu.sporny.org/
</code>
is
a
<a class="tref internalDFN" title="string" href="#dfn-string">
string
</a>,
the
type
<a class="tref internalDFN" title="coercion" href="#dfn-coercion">
coercion
</a>
rules
will
transform
the
value
into
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
when
processed
by
a
JSON-LD
Processor.
</p>
</div>
<div id="identifying-the-subject" class="section">
<h3>
<span class="secno">
<del class="diff-old">3.2
</del>
<ins class="diff-chg">3.3
</ins>
</span>
Identifying
the
Subject
</h3>
<p>
To
be
able
to
externally
reference
nodes,
it
is
important
that
each
node
has
an
unambiguous
identifier.
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
s
are
a
fundamental
concept
of
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>,
and
nodes
should
have
a
de-referencable
identifier
used
to
name
and
locate
them.
For
nodes
to
be
truly
linked,
de-referencing
the
identifier
should
result
in
a
representation
of
that
node.
Associating
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
with
a
node
tells
an
application
that
the
returned
document
contains
a
description
of
the
node
requested.
</p>
<p>
JSON-LD
documents
may
also
contain
descriptions
of
other
nodes,
so
it
is
necessary
to
be
able
to
uniquely
identify
each
node
which
may
be
externally
referenced.
</p>
<p>
A
<a class="tref internalDFN" title="subject" href="#dfn-subject">
subject
</a>
of
an
object
in
JSON
is
declared
using
the
<code>
@id
</code>
key.
The
subject
is
the
first
piece
of
information
needed
by
the
JSON-LD
processor
in
order
to
create
the
(subject,
property,
object)
tuple,
also
known
as
a
triple.
</p>
<del class="diff-old">{
...
  &quot;&quot;,
...
</del>
<pre class="example">{
<ins class="diff-chg">...
  &quot;<span class="diff">@id</span>&quot;: &quot;<span class="diff">http://example.org/people#joebob</span>&quot;,
...
</ins>
}
</pre>
<p>
The
example
above
would
set
the
subject
to
the
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
<code>
http://example.org/people#joebob
</code>.
</p>
<p>
<ins class="diff-new">A
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-new">
JSON
object
</ins></a><ins class="diff-new">
used
to
define
property
values
is
called
a
</ins><a class="tref internalDFN" title="subject_definition" href="#dfn-subject_definition"><ins class="diff-new">
subject
definition
</ins></a>.<a class="tref internalDFN" title="subject_definition" href="#dfn-subject_definition"><ins class="diff-new">
Subject
definitions
</ins></a><ins class="diff-new">
do
not
require
a
</ins><code><ins class="diff-new">
@id
</ins></code>,<ins class="diff-new">
in
which
case
they
are
considered
to
be
an
</ins><a class="tref internalDFN" title="unlabeled_node" href="#dfn-unlabeled_node"><ins class="diff-new">
unlabeled
node
</ins></a>.</p>
<p class="note">
To
ensure
the
best
possible
performance,
it
is
a
best
practice
to
put
the
<code>
@id
</code>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>
before
other
key-value
pairs
in
an
object.
If
it
isn't
listed
first,
processors
have
to
save
each
key-value
pair
until
<code>
@id
</code>
is
processed
before
they
can
start
generating
triples.
Not
specifying
the
<code>
@id
</code>
keyword
first
creates
a
memory
and
complexity
burden
for
one-pass
processors.
</p>
</div>
<div id="specifying-the-type" class="section">
<h3>
<span class="secno">
<del class="diff-old">3.3
</del>
<ins class="diff-chg">3.4
</ins>
</span>
Specifying
the
Type
</h3>
<p>
The
type
of
a
particular
subject
can
be
specified
using
the
<code>
@type
</code>
<del class="diff-old">keyword.
</del>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
<ins class="diff-chg">keyword
</ins></a>.
Specifying
the
type
in
this
way
will
generate
a
triple
of
the
form
(subject,
type,
type-
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
).
To
be
considered
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>,
types
<em class="rfc2119" title="must">
must
</em>
be
uniquely
identified
by
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
</p>
<del class="diff-old">{
...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;&quot;,
...
}
3.4
Strings
Regular
text
strings,
also
referred
to
as
string
value
s,
are
easily
expressed
using
regular
JSON
string
s.
{
...
  &quot;name&quot;: &quot;&quot;,
...
</del>
<pre class="example">{
<ins class="diff-chg">...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;<span class="diff">@type</span>&quot;: &quot;<span class="diff">http://xmlns.com/foaf/0.1/Person</span>&quot;,
...
</ins>
}
</pre>
</div>
<div id="string-internationalization" class="section">
<h3>
<span class="secno">
3.5
</span>
String
Internationalization
</h3>
<p>
<del class="diff-old">JSON-LD
makes
an
assumption
that
strings
</del>
<ins class="diff-chg">In
different
scenarios
it
is
important
to
annotate
a
</ins><a class="tref internalDFN" title="string" href="#dfn-string"><ins class="diff-chg">
string
</ins></a>
with
<del class="diff-old">associated
language
encoding
information
are
not
very
common
when
used
</del>
<ins class="diff-chg">its
language.
In
JSON-LD
this
is
possible
</ins>
in
<del class="diff-old">JavaScript
and
Web
Services.
Thus,
it
takes
</del>
a
<del class="diff-old">little
more
effort
</del>
<ins class="diff-chg">variety
of
ways.
Firstly,
it
is
possible
</ins>
to
<del class="diff-old">express
strings
with
associated
</del>
<ins class="diff-chg">define
a
default
</ins>
language
<del class="diff-old">information.
</del>
<ins class="diff-chg">for
a
JSON-LD
document
by
setting
the
</ins><code><ins class="diff-chg">
@language
</ins></code><ins class="diff-chg">
key
in
the
</ins><code><ins class="diff-chg">
@context
</ins></code><ins class="diff-chg">
or
in
a
</ins><a class="tref internalDFN" title="term" href="#dfn-term"><ins class="diff-chg">
term
</ins></a><ins class="diff-chg">
definition:
</ins>
</p>
<del class="diff-old">{
...
  &quot;name&quot;:
  {
    &quot;@value&quot;: &quot;花澄&quot;,
    &quot;@language&quot;: &quot;ja&quot;
  }
...
</del>
<pre class="example">{
  <span class="diff">&quot;@context&quot;:
<ins class="diff-chg">  {
    ...
    &quot;@language&quot;: &quot;ja&quot;
  },</span>
  &quot;name&quot;: <span class="diff">&quot;花澄&quot;</span>,
  &quot;occupation&quot;: <span class="diff">&quot;科学者&quot;</span>
</ins>
}
</pre>
<p>
The
example
above
would
<del class="diff-old">generate
a
string
value
for
花澄
and
</del>
associate
the
<code>
ja
</code>
language
code
with
the
<del class="diff-old">triple
that
is
generated.
</del>
<ins class="diff-chg">two
</ins><a class="tref internalDFN" title="string" href="#dfn-string"><ins class="diff-chg">
string
</ins></a><ins class="diff-chg">
s
</ins><em><ins class="diff-chg">
花澄
</ins></em><ins class="diff-chg">
and
</ins><em><ins class="diff-chg">
科学者
</ins></em>.
Languages
<em class="rfc2119" title="must">
must
</em>
be
expressed
in
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-BCP47">
BCP47
</a>
</cite>
]
format.
</p>
<del class="diff-old">3.6
Typed
Values
</del>
<p>
<del class="diff-old">A
value
with
an
associated
type,
also
known
as
a
typed
value
,
</del>
<ins class="diff-chg">It
</ins>
is
<del class="diff-old">indicated
by
associating
a
value
with
an
IRI
which
indicates
the
value's
type.
Typed
values
may
be
expressed
in
JSON-LD
in
three
ways:
By
utilizing
</del>
<ins class="diff-chg">possible
to
override
</ins>
the
<del class="diff-old">@type
keyword
when
defining
a
term
within
a
@context
section.
By
utilizing
</del>
<ins class="diff-chg">default
language
by
using
</ins>
the
expanded
form
<del class="diff-old">for
specifying
objects.
By
using
a
native
JSON
type.
The
first
example
uses
the
@type
keyword
to
express
</del>
<ins class="diff-chg">of
</ins>
a
<del class="diff-old">typed
</del>
value:
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
    &quot;modified&quot;:
    {
      &quot;@id&quot;: &quot;http://purl.org/dc/terms/modified&quot;,
      &quot;@type&quot;: &quot;xsd:dateTime&quot;
    }
  }
...
  &quot;modified&quot;: &quot;2010-05-29T14:17:39+02:00&quot;,
...
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;: {
    ...
    &quot;@language&quot;: &quot;ja&quot;
  },
  &quot;name&quot;: &quot;花澄&quot;,
  &quot;occupation&quot;: <span class="diff">{
    &quot;@value&quot;: &quot;Scientist&quot;,
    &quot;@language&quot;: &quot;en&quot;
  }</span>
</ins>
}
</pre>
<p>
<del class="diff-old">The
second
example
uses
</del>
<ins class="diff-chg">It
is
also
possible
to
override
the
default
language
or
specify
a
plain
value
by
omitting
the
</ins><code><ins class="diff-chg">
@language
</ins></code><ins class="diff-chg">
tag
or
setting
it
to
</ins><code><ins class="diff-chg">
null
</ins></code><ins class="diff-chg">
when
expressing
</ins>
the
expanded
<del class="diff-old">form
for
specifying
objects:
</del>
<ins class="diff-chg">value:
</ins>
</p>
<del class="diff-old">{
...
  &quot;modified&quot;:
  {
    &quot;@value&quot;: &quot;2010-05-29T14:17:39+02:00&quot;,
    &quot;@type&quot;: &quot;xsd:dateTime&quot;
  }
...
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;: {
    ...
    &quot;@language&quot;: &quot;ja&quot;
  },
  &quot;name&quot;: <span class="diff">{
    &quot;@value&quot;: &quot;花澄&quot;
  },</span>
  &quot;occupation&quot;: <span class="diff"> {
    &quot;@value&quot;: &quot;Ninja&quot;,
    &quot;@language&quot;: &quot;en&quot;
  }</span>,
  &quot;speciality&quot;: &quot;手裏剣&quot;
</ins>
}
</pre>
<del class="diff-old">Both
examples
above
would
generate
an
object
with
the
</del>
<p class="note">
<ins class="diff-chg">Please
note
that
language
associations
</ins><em class="rfc2119" title="must"><ins class="diff-chg">
must
</ins></em><ins class="diff-chg">
only
be
applied
to
plain
literal
</ins><a class="tref internalDFN" title="string" href="#dfn-string"><ins class="diff-chg">
string
</ins></a><ins class="diff-chg">
s.
That
is,
</ins><a class="tref internalDFN" title="typed_value" href="#dfn-typed_value"><ins class="diff-chg">
typed
</ins>
value
<del class="diff-old">of
2010-05-29T14:17:39+02:00
and
the
</del>
</a>
<ins class="diff-chg">s
or
values
that
are
subject
to
</ins><a href="#type-coercion">
type
<del class="diff-old">of
http://www.w3.org/2001/XMLSchema#dateTime
.
</del>
<ins class="diff-chg">coercion
</ins></a><ins class="diff-chg">
won't
be
language
tagged.
</ins>
</p>
<p>
<del class="diff-old">The
third
example
uses
a
built-in
native
JSON
type,
</del>
<ins class="diff-chg">To
clear
the
default
language
for
</ins>
a
<del class="diff-old">number
,
</del>
<ins class="diff-chg">subtree,
</ins><code><ins class="diff-chg">
@language
</ins></code><ins class="diff-chg">
can
be
set
</ins>
to
<del class="diff-old">express
a
type:
{
...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;age&quot;:
...
}
The
example
above
is
really
just
</del>
<code>
<ins class="diff-chg">null
</ins></code><ins class="diff-chg">
in
</ins>
a
<del class="diff-old">shorthand
for
the
following:
</del>
<a class="tref internalDFN" title="local_context" href="#dfn-local_context">
<ins class="diff-chg">local
context
</ins></a><ins class="diff-chg">
as
follows:
</ins>
</p>
<del class="diff-old">{
...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;age&quot;:
  {
    &quot;@value&quot;: &quot;31&quot;,
    &quot;@type&quot;: &quot;http://www.w3.org/2001/XMLSchema#integer&quot;
  }
...
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;: {
    ...
    &quot;@language&quot;: &quot;ja&quot;
  },
  &quot;name&quot;: &quot;花澄&quot;,
  &quot;details&quot;: {
</ins><span class="diff">    &quot;@context&quot;: {<ins class="diff-chg">
      &quot;@language&quot;: null
    },</span>
    &quot;occupation&quot;: &quot;Ninja&quot;
  }
</ins>
}
</pre>
<p class="note">
<del class="diff-old">The
@type
keyword
is
also
used
</del>
<ins class="diff-chg">JSON-LD
allows
</ins>
to
associate
<del class="diff-old">a
type
</del>
<ins class="diff-chg">language
information
</ins>
with
<del class="diff-old">a
subject
.
Although
the
same
keyword
is
used
in
both
places,
the
concept
of
an
object
type
and
a
value
type
are
different.
This
is
similar
to
object-oriented
programming
languages
where
both
scalar
and
structured
types
use
the
same
class
inheritance
mechanism,
even
though
scalar
types
and
structured
types
are
inherently
different.
</del>
<ins class="diff-chg">terms.
See
</ins><a href="#expanded-term-definition"><ins class="diff-chg">
Expanded
Term
Definition
</ins></a><ins class="diff-chg">
for
more
details.
</ins>
</p>
</div>
<div id="sets-and-lists" class="section">
<h3>
<span class="secno">
<del class="diff-old">3.7
</del>
<ins class="diff-chg">3.6
</ins>
</span>
<del class="diff-old">Multiple
Objects
for
a
Single
Property
</del>
<ins class="diff-chg">Sets
and
Lists
</ins>
</h3>
<p>
A
JSON-LD
author
can
express
multiple
values
in
a
compact
way
by
using
<a class="tref internalDFN" title="array" href="#dfn-array">
array
</a>
s.
<del class="diff-old">If
a
subject
has
multiple
values
for
the
same
property,
the
author
may
express
each
property
as
an
array
.
In
JSON-LD,
multiple
objects
on
a
property
are
not
ordered.
This
is
</del>
<ins class="diff-chg">But,
</ins>
because
graphs
<del class="diff-old">are
inherently
unordered
data
structures.
To
learn
more
about
creating
ordered
collections
in
JSON-LD,
see
the
section
on
Lists
.
{
...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;nick&quot;: ,
...
}
The
markup
shown
above
would
generate
the
following
triples:
&lt;http://example.org/people#joebob&gt;
   &lt;http://xmlns.com/foaf/0.1/nick&gt;
      &quot;joe&quot; .
&lt;http://example.org/people#joebob&gt;
   &lt;http://xmlns.com/foaf/0.1/nick&gt;
      &quot;bob&quot; .
&lt;http://example.org/people#joebob&gt;
   &lt;http://xmlns.com/foaf/0.1/nick&gt;
&quot;jaybee&quot;
.
3.8
Multiple
Values
for
a
Single
Property
Multiple
value
s
may
also
be
expressed
using
the
expanded
form
for
object
s:
{
  &quot;@id&quot;: &quot;http://example.org/articles/8&quot;,
  &quot;dc:title&quot;:
  [
    {
      &quot;@value&quot;: &quot;Das Kapital&quot;,
      &quot;@language&quot;: &quot;de&quot;
    },
    {
      &quot;@value&quot;: &quot;Capital&quot;,
      &quot;@language&quot;: &quot;en&quot;
    }
  ]
}
The
markup
shown
above
would
generate
the
following
triples:
&lt;http://example.org/articles/8&gt;
   &lt;http://purl.org/dc/terms/title&gt;
      &quot;Das Kapital&quot;@de .
&lt;http://example.org/articles/8&gt;
   &lt;http://purl.org/dc/terms/title&gt;
&quot;Capital&quot;@en
.
3.9
Lists
Because
graphs
</del>
do
not
describe
ordering
for
links
between
nodes,
in
contrast
to
plain
JSON,
<del class="diff-old">multi-valued
properties
</del>
<ins class="diff-chg">arrays
</ins>
in
JSON-LD
do
not
provide
an
ordering
of
the
listed
<del class="diff-old">objects.
</del>
<ins class="diff-chg">objects
by
default.
</ins>
For
example,
consider
the
following
simple
document:
</p>
<del class="diff-old">  {
...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;nick&quot;: ,
...
</del>
<pre class="example">{
<ins class="diff-chg">...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;nick&quot;: <span class="diff">[ &quot;joe&quot;, &quot;bob&quot;, &quot;jaybee&quot; ]</span>,
...
</ins>
}
</pre>
<p>
<del class="diff-old">This
results
</del>
<ins class="diff-chg">The
markup
shown
above
would
result
</ins>
in
three
triples
being
generated,
each
relating
the
subject
to
an
individual
object,
with
no
inherent
<del class="diff-old">order.
</del>
<ins class="diff-chg">order:
</ins>
</p>
<pre class="example">&lt;http://example.org/people#joebob&gt;
<ins class="diff-new">   &lt;http://xmlns.com/foaf/0.1/nick&gt;
      &quot;joe&quot; .
&lt;http://example.org/people#joebob&gt;
   &lt;http://xmlns.com/foaf/0.1/nick&gt;
      &quot;bob&quot; .
&lt;http://example.org/people#joebob&gt;
   &lt;http://xmlns.com/foaf/0.1/nick&gt;
&quot;jaybee&quot;
.
</ins></pre><p><ins class="diff-new">
Multiple
values
may
also
be
expressed
using
the
expanded
object
form:
</ins></p><pre class="example">{<ins class="diff-new">
  &quot;@id&quot;: &quot;http://example.org/articles/8&quot;,
  &quot;dc:title&quot;: <span class="diff">
  [
    {
      &quot;@value&quot;: &quot;Das Kapital&quot;,
      &quot;@language&quot;: &quot;de&quot;
    },
    {
      &quot;@value&quot;: &quot;Capital&quot;,
      &quot;@language&quot;: &quot;en&quot;
    }
  ]</span>
}
</ins></pre><p><ins class="diff-new">
The
markup
shown
above
would
generate
the
following
triples,
again
with
no
inherent
order:
</ins></p><pre class="example">&lt;http://example.org/articles/8&gt;<ins class="diff-new">
   &lt;http://purl.org/dc/terms/title&gt;
      &quot;Das Kapital&quot;@de .
&lt;http://example.org/articles/8&gt;
   &lt;http://purl.org/dc/terms/title&gt;
&quot;Capital&quot;@en
.
</ins></pre>
<p>
As
the
notion
of
ordered
collections
is
rather
important
in
data
modeling,
it
is
useful
to
have
specific
language
support.
In
JSON-LD,
a
list
may
be
represented
using
the
<code>
@list
</code>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>
as
follows:
</p>
<del class="diff-old">  {
...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;foaf:nick&quot;:
  {
    &quot;@list&quot;: [ &quot;joe&quot;, &quot;bob&quot;, &quot;jaybee&quot; ]
  },
...
</del>
<pre class="example">{
<ins class="diff-chg">...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;foaf:nick&quot;:
</ins>  <span class="diff">{<ins class="diff-chg">
    &quot;@list&quot;: [ &quot;joe&quot;, &quot;bob&quot;, &quot;jaybee&quot; ]
  }</span>,
...
</ins>
}
</pre>
<p>
This
describes
the
use
of
this
<a class="tref internalDFN" title="array" href="#dfn-array">
array
</a>
as
being
ordered,
and
order
is
maintained
through
<del class="diff-old">alternate
representations
</del>
<ins class="diff-chg">operations
such
</ins>
as
<del class="diff-old">described
in
[
JSON-LD-API
].
</del>
<a href="#expansion">
<ins class="diff-chg">Expansion
</ins></a>,<a href="#compaction"><ins class="diff-chg">
Compaction
</ins></a>,<ins class="diff-chg">
and
</ins><a href="#framing"><ins class="diff-chg">
Framing
</ins></a>.
If
every
use
of
a
given
multi-valued
property
is
a
list,
this
may
be
abbreviated
by
setting
<code>
@container
</code>
to
<code>
@list
</code>
in
the
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>:
</p>
<del class="diff-old">  {
  &quot;@context&quot;:
  {
    ...
    &quot;nick&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/nick&quot;,
      &quot;@container&quot;: &quot;@list&quot;
    }
  },
...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;nick&quot;: ,
...
</del>
<pre class="example">{
  <span class="diff">&quot;@context&quot;:
<ins class="diff-chg">  {
    ...
    &quot;nick&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/nick&quot;,
      &quot;@container&quot;: &quot;@list&quot;
    }
  }</span>,
...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;nick&quot;: <span class="diff">[ &quot;joe&quot;, &quot;bob&quot;, &quot;jaybee&quot; ]</span>,
...
</ins>
}
</pre>
<p class="note">
List
<del class="diff-old">coercion
</del>
<ins class="diff-chg">of
lists
are
not
allowed
in
this
version
of
JSON-LD.
If
a
list
of
lists
</ins>
is
<del class="diff-old">specified
within
</del>
<ins class="diff-chg">detected,
a
JSON-LD
processor
will
throw
</ins>
an
<del class="diff-old">expanded
term
definition
using
</del>
<ins class="diff-chg">exception.
</ins></p><p><ins class="diff-chg">
Similarly
to
</ins><code><ins class="diff-chg">
@list
</ins></code>,<ins class="diff-chg">
there
exists
</ins>
the
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
<ins class="diff-new">keyword
</ins></a>
<code>
<del class="diff-old">@container
</del>
<ins class="diff-chg">@set
</ins>
</code>
<del class="diff-old">key.
The
value
</del>
<ins class="diff-chg">to
describe
unordered
sets.
While
its
use
in
the
body
</ins>
of
<del class="diff-old">this
key,
if
present,
</del>
<ins class="diff-chg">a
JSON-LD
document
represents
just
syntactic
sugar
that
</ins>
<em class="rfc2119" title="must">
must
</em>
be
<ins class="diff-new">optimized
away
when
processing
the
document,
it
is
very
helpful
for
</ins><a href="#compaction"><ins class="diff-new">
Compaction
</ins></a><ins class="diff-new">
and
</ins><a href="#framing"><ins class="diff-new">
Framing
</ins></a>.<ins class="diff-new">
The
value
of
terms
associated
with
a
</ins><code><ins class="diff-new">
@set
</ins></code><ins class="diff-new">
-
or
</ins>
<code>
@list
<del class="diff-old">.
This
indicates
that
</del>
</code>
<ins class="diff-chg">-
</ins><code><ins class="diff-chg">
@container
</ins></code><ins class="diff-chg">
are
always
represented
in
the
form
of
an
</ins><a class="tref internalDFN" title="array" href="#dfn-array">
array
<del class="diff-old">values
</del>
</a>
<ins class="diff-chg">-
even
if
there
is
just
a
single
value.
This
makes
post-processing
</ins>
of
<del class="diff-old">keys
coerced
</del>
<ins class="diff-chg">the
data
easier
</ins>
as
<ins class="diff-new">the
data
is
in
a
deterministic
form.
If
no
such
</ins>
<code>
<del class="diff-old">@list
</del>
<ins class="diff-chg">@container
</ins>
</code>
<ins class="diff-new">is
specified,
single
values
</ins>
are
<ins class="diff-new">optimized
</ins>
to
<del class="diff-old">be
serialized
as
</del>
a
<del class="diff-old">List
.
</del>
<ins class="diff-chg">non-array
form.
</ins>
</p>
<p class="note">
<del class="diff-old">List
</del>
<ins class="diff-chg">The
use
</ins>
of
<del class="diff-old">lists
are
not
allowed
</del>
<code>
<ins class="diff-chg">@container
</ins></code>
in
<del class="diff-old">this
version
</del>
<ins class="diff-chg">the
body
</ins>
of
<del class="diff-old">JSON-LD.
If
</del>
a
<del class="diff-old">list
of
lists
</del>
<ins class="diff-chg">JSON-LD
document,
i.e.,
outside
</ins><code><ins class="diff-chg">
@context
</ins></code>
is
<del class="diff-old">detected,
a
</del>
<ins class="diff-chg">ignored
by
</ins>
JSON-LD
<del class="diff-old">processor
will
throw
an
exception.
</del>
<ins class="diff-chg">processors.
</ins>
</p>
</div>
</div>
<div id="advanced-concepts" class="section">
<h2>
<span class="secno">
4.
</span>
Advanced
Concepts
</h2>
<p>
JSON-LD
has
a
number
of
features
that
provide
functionality
above
and
beyond
the
core
functionality
described
above.
The
following
sections
outline
the
features
that
are
specific
to
JSON-LD.
</p>
<div id="typed-values" class="section">
<h3>
<span class="secno">
4.1
</span>
<ins class="diff-new">Typed
Values
</ins></h3><p><ins class="diff-new">
A
value
with
an
associated
type,
also
known
as
a
</ins><dfn title="typed_value" id="dfn-typed_value"><ins class="diff-new">
typed
value
</ins></dfn>,<ins class="diff-new">
is
indicated
by
associating
a
value
with
an
</ins><a class="tref internalDFN" title="iri" href="#dfn-iri"><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr></a><ins class="diff-new">
which
indicates
the
value's
type.
Typed
values
may
be
expressed
in
JSON-LD
in
three
ways:
</ins></p><ol><li><ins class="diff-new">
By
utilizing
the
</ins><code><ins class="diff-new">
@type
</ins></code><a class="tref internalDFN" title="keyword" href="#dfn-keyword"><ins class="diff-new">
keyword
</ins></a><ins class="diff-new">
when
defining
a
</ins><a class="tref internalDFN" title="term" href="#dfn-term"><ins class="diff-new">
term
</ins></a><ins class="diff-new">
within
a
</ins><code><ins class="diff-new">
@context
</ins></code><ins class="diff-new">
section.
</ins></li><li><ins class="diff-new">
By
utilizing
the
expanded
form
for
specifying
objects.
</ins></li><li><ins class="diff-new">
By
using
a
native
JSON
type.
</ins></li></ol><p><ins class="diff-new">
The
first
example
uses
the
</ins><code><ins class="diff-new">
@type
</ins></code><ins class="diff-new">
keyword
to
express
a
typed
value:
</ins></p><pre class="example">{  <span class="diff">&quot;@context&quot;:<ins class="diff-new">
  {
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
    &quot;modified&quot;:
    {
      &quot;@id&quot;: &quot;http://purl.org/dc/terms/modified&quot;,
      &quot;@type&quot;: &quot;xsd:dateTime&quot;
    }
  }</span>
...
  &quot;modified&quot;: &quot;2010-05-29T14:17:39+02:00&quot;,
...
}
</ins></pre><p><ins class="diff-new">
The
second
example
uses
the
expanded
form
for
specifying
objects:
</ins></p><pre class="example">{<ins class="diff-new">
...
  &quot;modified&quot;:
</ins>  <span class="diff">{<ins class="diff-new">
    &quot;@value&quot;: &quot;2010-05-29T14:17:39+02:00&quot;,
    &quot;@type&quot;: &quot;xsd:dateTime&quot;
  }</span>
...
}
</ins></pre><p><ins class="diff-new">
Both
examples
above
would
generate
an
object
with
the
value
of
</ins><code><ins class="diff-new">
2010-05-29T14:17:39+02:00
</ins></code><ins class="diff-new">
and
the
type
of
</ins><code><ins class="diff-new">
http://www.w3.org/2001/XMLSchema#dateTime
</ins></code>.</p><p><ins class="diff-new">
The
third
example
uses
a
built-in
native
JSON
type,
a
</ins><a class="tref internalDFN" title="number" href="#dfn-number"><ins class="diff-new">
number
</ins></a>,<ins class="diff-new">
to
express
a
type:
</ins></p><pre class="example">{<ins class="diff-new">
...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;age&quot;: <span class="diff">31</span>
...
}
</ins></pre><p><ins class="diff-new">
The
example
above
is
really
just
a
shorthand
for
the
following:
</ins></p><pre class="example">{<ins class="diff-new">
...
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;age&quot;:
</ins>  <span class="diff">{<ins class="diff-new">
    &quot;@value&quot;: &quot;31&quot;,
    &quot;@type&quot;: &quot;http://www.w3.org/2001/XMLSchema#integer&quot;
  }</span>
...
}
</ins></pre><p class="note"><ins class="diff-new">
The
</ins><code><ins class="diff-new">
@type
</ins></code><a class="tref internalDFN" title="keyword" href="#dfn-keyword"><ins class="diff-new">
keyword
</ins></a><ins class="diff-new">
is
also
used
to
associate
a
type
with
a
</ins><a class="tref internalDFN" title="subject" href="#dfn-subject"><ins class="diff-new">
subject
</ins></a>.<ins class="diff-new">
Although
the
same
keyword
is
used
in
both
places,
the
concept
of
an
</ins><em><ins class="diff-new">
object
type
</ins></em><ins class="diff-new">
and
a
</ins><em><ins class="diff-new">
value
type
</ins></em><ins class="diff-new">
are
different.
This
is
similar
to
object-oriented
programming
languages
where
both
scalar
and
structured
types
use
the
same
class
inheritance
mechanism,
even
though
scalar
types
and
structured
types
are
inherently
different.
</ins></p></div><div id="compact-iris" class="section"><h3><span class="secno"><ins class="diff-new">
4.2
</ins></span>
Compact
IRIs
</h3>
<p>
<a class="tref internalDFN" title="term" href="#dfn-term">
Term
</a>
s
in
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>
documents
may
draw
from
a
number
of
different
<a class="tref internalDFN" title="vocabulary" href="#dfn-vocabulary">
vocabularies
</a>.
At
times,
declaring
every
single
term
that
a
document
uses
can
require
the
developer
to
declare
tens,
if
not
hundreds
of
potential
<a class="tref internalDFN" title="vocabulary" href="#dfn-vocabulary">
vocabulary
</a>
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
that
are
used
across
an
application.
This
is
a
concern
for
at
least
three
<del class="diff-old">reasons;
</del>
<ins class="diff-chg">reasons:
</ins>
the
first
is
the
cognitive
load
on
the
developer
of
remembering
all
of
the
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s,
the
second
is
the
serialized
size
of
the
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
if
it
is
specified
inline,
the
third
is
future-proofing
embedded
application
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
s
that
may
not
be
easy
to
change
after
they
are
deployed.
In
order
to
address
these
issues,
the
concept
of
a
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
is
introduced.
</p>
<p>
A
<dfn title="compact_iri" id="dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</dfn>
is
a
way
of
expressing
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
using
a
<em>
prefix
</em>
and
<em>
suffix
</em>.
Generally,
these
prefixes
are
used
by
concatenating
the
<em>
prefix
</em>
and
a
<em>
suffix
</em>,
which
is
separated
by
a
colon
(
<code>:
</code>
).
The
<dfn title="prefix" id="dfn-prefix">
prefix
</dfn>
is
a
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
taken
from
the
<a class="tref internalDFN" title="active_context" href="#dfn-active_context">
active
context
</a>
and
is
a
short
string
identifying
a
particular
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
in
a
JSON-LD
document.
For
example,
the
prefix
<code>
foaf
</code>
may
be
used
as
a
short
hand
for
the
Friend-of-a-Friend
vocabulary,
which
is
identified
using
the
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
<code>
http://xmlns.com/foaf/0.1/
</code>.
A
developer
may
append
any
of
the
FOAF
<a class="tref internalDFN" title="vocabulary" href="#dfn-vocabulary">
vocabulary
</a>
terms
to
the
end
of
the
prefix
to
specify
a
short-hand
version
of
the
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
for
the
<a class="tref internalDFN" title="vocabulary" href="#dfn-vocabulary">
vocabulary
</a>
term.
For
example,
<code>
foaf:name
</code>
would
be
expanded
out
to
the
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
<code>
http://xmlns.com/foaf/0.1/name
</code>.
Instead
of
having
to
remember
and
type
out
the
entire
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>,
the
developer
can
instead
use
the
prefix
in
their
JSON-LD
markup.
</p>
<p>
Terms
are
interpreted
as
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
s
if
they
contain
at
least
one
colon
and
the
first
colon
is
not
followed
by
two
slashes
(
<code>
//
</code>,
as
in
<code>
http://example.com
</code>
).
To
generate
the
full
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>,
the
value
is
first
split
into
a
<em>
prefix
</em>
and
<em>
suffix
</em>
at
the
first
occurrence
of
a
colon
(
<code>:
</code>
).
If
the
<a class="tref internalDFN" title="active_context" href="#dfn-active_context">
active
context
</a>
contains
a
term
mapping
for
<em>
prefix
</em>,
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
is
generated
by
prepending
the
mapped
<em>
prefix
</em>
to
the
(possibly
empty)
<em>
suffix
</em>
using
textual
concatenation.
If
no
prefix
mapping
is
defined,
the
value
is
<del class="diff-old">used
directly
</del>
<ins class="diff-chg">interpreted
</ins>
as
an
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
If
the
prefix
is
an
underscore
(
<code>
_
</code>
),
the
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
remains
unchanged.
This
effectively
means
that
every
term
containing
a
colon
will
be
interpreted
by
a
JSON-LD
processor
as
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>.
</p>
<p>
The
ability
to
use
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
IRIs
</a>
reduces
the
need
for
developers
to
declare
every
<a class="tref internalDFN" title="vocabulary" href="#dfn-vocabulary">
vocabulary
</a>
term
that
they
intend
to
use
in
the
JSON-LD
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>.
This
reduces
stand-alone
JSON-LD
document
serialization
size
because
every
<a class="tref internalDFN" title="vocabulary" href="#dfn-vocabulary">
vocabulary
</a>
term
need
not
be
declared
in
the
embedded
context.
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
Compact
IRIs
</a>
also
reduces
the
cognitive
load
on
the
developer.
It
is
far
easier
to
remember
<code>
foaf:name
</code>
than
it
is
to
remember
<code>
http://xmlns.com/foaf/0.1/name
</code>.
The
use
of
prefixes
also
ensures
that
a
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
document
does
not
have
to
be
updated
in
lock-step
with
an
externally
defined
<a class="tref internalDFN" title="vocabulary" href="#dfn-vocabulary">
vocabulary
</a>.
Without
prefixes,
a
developer
would
need
to
keep
their
application
context
terms
in
lock-step
with
an
externally
defined
vocabulary.
Rather,
by
just
declaring
the
<a class="tref internalDFN" title="vocabulary" href="#dfn-vocabulary">
vocabulary
</a>
prefix,
one
can
use
new
terms
as
they're
declared
without
having
to
update
the
application's
JSON-LD
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>.
</p>
<p>
Consider
the
following
example:
</p>
<del class="diff-old">  {
  &quot;@context&quot;:
  {


  },
  &quot;@id&quot;: &quot;http://example.org/library&quot;,
  &quot;@type&quot;: ,
  :
  {
    &quot;@id&quot;: &quot;http://example.org/library/the-republic&quot;,
    &quot;@type&quot;: ,
    : &quot;Plato&quot;,
    : &quot;The Republic&quot;,
    :
    {
      &quot;@id&quot;: &quot;http://example.org/library/the-republic#introduction&quot;,
      &quot;@type&quot;: ,
      : &quot;An introductory chapter on The Republic.&quot;,
      : &quot;The Introduction&quot;
    }
  }
</del>
  <pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
</ins>    <span class="diff">&quot;dc&quot;: &quot;http://purl.org/dc/elements/1.1/&quot;,</span>    <span class="diff">&quot;ex&quot;: &quot;http://example.org/vocab#&quot;</span><ins class="diff-chg">
  },
  &quot;@id&quot;: &quot;http://example.org/library&quot;,
  &quot;@type&quot;: <span class="diff">&quot;ex:Library&quot;</span>,
</ins>  <span class="diff">&quot;ex:contains&quot;</span>:<ins class="diff-chg">
  {
    &quot;@id&quot;: &quot;http://example.org/library/the-republic&quot;,
    &quot;@type&quot;: <span class="diff">&quot;ex:Book&quot;</span>,
</ins>    <span class="diff">&quot;dc:creator&quot;</span>: &quot;Plato&quot;,    <span class="diff">&quot;dc:title&quot;</span>: &quot;The Republic&quot;,    <span class="diff">&quot;ex:contains&quot;</span>:<ins class="diff-chg">
    {
      &quot;@id&quot;: &quot;http://example.org/library/the-republic#introduction&quot;,
      &quot;@type&quot;: <span class="diff">&quot;ex:Chapter&quot;</span>,
</ins>      <span class="diff">&quot;dc:description&quot;</span>: &quot;An introductory chapter on The Republic.&quot;,      <span class="diff">&quot;dc:title&quot;</span>: &quot;The Introduction&quot;<ins class="diff-chg">
    }
  }
</ins>
}
</pre>
<p>
In
this
example,
two
different
<a class="tref internalDFN" title="vocabulary" href="#dfn-vocabulary">
vocabularies
</a>
are
referred
to
using
prefixes.
Those
prefixes
are
then
used
as
type
and
property
values
using
the
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
<code>
prefix:suffix
</code>
notation.
</p>
<p>
It's
also
possible
to
use
compact
IRIs
within
the
context
as
shown
in
the
following
example:
</p>
<del class="diff-old">  {
  &quot;@context&quot;:
  {
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;,
    : { &quot;@type&quot;: &quot;@id&quot; },
    &quot;picture&quot;: { &quot;@id&quot;: , &quot;@type&quot;: &quot;@id&quot; }
  },
  &quot;@subject&quot;: &quot;http://me.markus-lanthaler.com/&quot;,
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Markus Lanthaler&quot;,
  &quot;foaf:homepage&quot;: &quot;http://www.markus-lanthaler.com/&quot;,
  &quot;picture&quot;: &quot;http://twitter.com/account/profile_image/markuslanthaler&quot;
</del>
  <pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;,
</ins>    <span class="diff">&quot;foaf:homepage&quot;</span>: { &quot;@type&quot;: &quot;@id&quot; },<ins class="diff-chg">
    &quot;picture&quot;: { &quot;@id&quot;: <span class="diff">&quot;foaf:depiction&quot;</span>, &quot;@type&quot;: &quot;@id&quot; }
  },
  &quot;@subject&quot;: &quot;http://me.markus-lanthaler.com/&quot;,
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Markus Lanthaler&quot;,
  &quot;foaf:homepage&quot;: &quot;http://www.markus-lanthaler.com/&quot;,
  &quot;picture&quot;: &quot;http://twitter.com/account/profile_image/markuslanthaler&quot;
</ins>
}
</pre>
<p>
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
Compact
IRIs
</a>,
also
known
as
CURIEs,
are
defined
more
formally
in
RDFa
Core
1.1,
<cite>
<a href="http://www.w3.org/TR/rdfa-core/#s_curies">
Section
6
&quot;CURIE
Syntax
Definition&quot;
</a>
</cite>
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-RDFA-CORE">
RDFA-CORE
</a>
</cite>
].
JSON-LD
does
not
support
the
square-bracketed
CURIE
syntax
as
the
mechanism
is
not
required
to
disambiguate
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
s
in
a
JSON-LD
document
like
it
is
in
HTML
documents.
</p>
</div>
<div id="external-contexts" class="section">
<h3>
<span class="secno">
<del class="diff-old">4.2
</del>
<ins class="diff-chg">4.3
</ins>
</span>
External
Contexts
</h3>
<p>
Authors
may
choose
to
declare
JSON-LD
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
s
in
external
documents
to
promote
re-use
of
contexts
as
well
as
reduce
the
size
of
JSON-LD
documents.
</p>
<p>
In
order
to
use
an
external
context,
an
author
<em class="rfc2119" title="must">
must
</em>
specify
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
to
a
valid
JSON-LD
document.
The
referenced
document
<em class="rfc2119" title="must">
must
</em>
have
a
top-level
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
<del class="diff-old">Object
</del>
<ins class="diff-chg">object
</ins>
</a>.
The
value
of
any
<code>
@context
</code>
key
within
that
object
is
substituted
for
the
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
within
the
referencing
document
to
have
the
same
effect
as
if
the
value
were
specified
inline
within
the
referencing
document.
</p>
<p>
The
following
example
demonstrates
the
use
of
an
external
context:
</p>
<del class="diff-old">{
  ,
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
</del>
<pre class="example">{
  <span class="diff">&quot;@context&quot;: &quot;http://json-ld.org/contexts/person&quot;</span>,
<ins class="diff-chg">  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
</ins>
}
</pre>
<p>
Authors
may
also
import
multiple
contexts
or
a
combination
of
external
and
local
contexts
by
specifying
a
list
of
contexts:
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  [
    &quot;http://json-ld.org/contexts/person&quot;,
    {
      &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
    },
    &quot;http://json-ld.org/contexts/event&quot;,
  ]
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
  &quot;celebrates&quot;:
  {
    &quot;@type&quot;: &quot;Event&quot;,
    &quot;description&quot;: &quot;International Talk Like a Pirate Day&quot;,
    &quot;date&quot;: &quot;R/2011-09-19&quot;
  }
</del>
<pre class="example">{
  <span class="diff">&quot;@context&quot;:
<ins class="diff-chg">  [
    &quot;http://json-ld.org/contexts/person&quot;,
    {
      &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
    },
    &quot;http://json-ld.org/contexts/event&quot;,
  ]</span>
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
</ins>  <span class="diff">&quot;celebrates&quot;:<ins class="diff-chg">
  {
    &quot;@type&quot;: &quot;Event&quot;,
    &quot;description&quot;: &quot;International Talk Like a Pirate Day&quot;,
    &quot;date&quot;: &quot;R/2011-09-19&quot;
  }</span>
</ins>
}
</pre>
<p>
Each
context
in
a
list
will
be
evaluated
in-order.
Duplicate
mappings
among
the
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
s
<em class="rfc2119" title="must">
must
</em>
be
overwritten
on
a
last-defined-overrides
basis.
The
context
list
<em class="rfc2119" title="must">
must
</em>
contain
either
de-referenceable
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
s
or
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
<del class="diff-old">Object
</del>
<ins class="diff-chg">object
</ins>
</a>
s
that
conform
to
the
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
syntax
as
described
in
this
document.
</p>
<p>
An
author
may
nest
contexts
within
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
s,
with
the
more
deeply
nested
contexts
overriding
the
values
in
previously
defined
contexts:
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    &quot;name&quot;: &quot;http://example.com/person#name&quot;,
    &quot;details&quot;: &quot;http://example.com/person#details&quot;
  },
  &quot;&quot;: &quot;Markus Lanthaler&quot;,
  ...
  &quot;details&quot;:
  {

    &quot;&quot;: &quot;Graz University of Technology&quot;
  }
</del>
<pre class="example">{
  <span class="diff">&quot;@context&quot;:
<ins class="diff-chg">  {
    &quot;name&quot;: &quot;http://example.com/person#name&quot;,
    &quot;details&quot;: &quot;http://example.com/person#details&quot;
  },</span>
  &quot;<span class="diff">name</span>&quot;: &quot;Markus Lanthaler&quot;,
  ...
  &quot;details&quot;:
  {
</ins>    <span class="diff">&quot;@context&quot;: { &quot;name&quot;: &quot;http://example.com/organization#name&quot; },</span><ins class="diff-chg">
    &quot;<span class="diff">name</span>&quot;: &quot;Graz University of Technology&quot;
  }
</ins>
}
</pre>
<p>
In
the
example
above,
the
<code>
name
</code>
prefix
is
overridden
in
the
more
deeply
nested
<code>
details
</code>
structure.
Note
that
this
is
rarely
a
good
authoring
practice
and
is
typically
used
when
the
JSON
object
has
legacy
applications
using
the
structure
of
the
object.
</p>
<p>
External
JSON-LD
context
documents
<em class="rfc2119" title="may">
may
</em>
contain
extra
information
located
outside
of
the
<code>
@context
</code>
key,
such
as
documentation
about
the
<a class="tref internalDFN" title="prefix" href="#dfn-prefix">
prefixes
</a>
declared
in
the
document.
When
importing
a
<code>
@context
</code>
value
from
an
external
JSON-LD
context
document,
any
extra
information
contained
outside
of
the
<code>
@context
</code>
value
<em class="rfc2119" title="must">
must
</em>
be
discarded.
It
is
also
<em class="rfc2119" title="recommended">
recommended
</em>
that
a
human-readable
document
encoded
in
HTML+RDFa
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-HTML-RDFA">
HTML-RDFA
</a>
</cite>
]
or
other
Linked
Data
compatible
format
is
served
as
well
to
explain
the
correct
usage
of
the
JSON-LD
context
document.
</p>
</div>
<div id="referencing-contexts-from-json-documents" class="section">
<h3>
<span class="secno">
<del class="diff-old">4.3
</del>
<ins class="diff-chg">4.4
</ins>
</span>
Referencing
Contexts
from
JSON
Documents
</h3>
<p>
Ordinary
JSON
documents
can
be
transformed
<del class="diff-old">in
</del>
<ins class="diff-chg">into
</ins>
JSON-LD
documents
by
referencing
to
an
external
JSON-LD
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
in
an
HTTP
Link
Header.
Doing
this
allows
JSON
to
be
unambiguously
machine-readable
without
requiring
developers
to
drastically
change
their
workflow
and
provides
an
upgrade
path
for
existing
infrastructure
without
breaking
existing
clients
that
rely
on
the
<code>
application/json
</code>
media
type.
</p>
<p>
In
order
to
use
an
external
context
with
an
ordinary
JSON
document,
an
author
<em class="rfc2119" title="must">
must
</em>
specify
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
to
a
valid
JSON-LD
document
in
an
HTTP
Link
Header
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-RFC5988">
RFC5988
</a>
</cite>
]
using
the
<code>
describedby
</code>
link
relation.
The
referenced
document
<em class="rfc2119" title="must">
must
</em>
have
a
top-level
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
<del class="diff-old">Object
</del>
<ins class="diff-chg">object
</ins>
</a>.
The
<code>
@context
</code>
subtree
within
that
object
is
added
to
the
top-level
object
of
the
referencing
document.
If
an
array
is
at
the
top-level
of
the
referencing
document
and
its
items
are
objects,
the
<code>
@context
</code>
subtree
is
added
to
all
array
items.
All
extra
information
located
outside
of
the
<code>
@context
</code>
subtree
in
the
referenced
document
<em class="rfc2119" title="must">
must
</em>
be
discarded.
</p>
<p>
The
following
example
demonstrates
the
use
of
an
external
context
with
an
ordinary
JSON
document:
</p>
<del class="diff-old">GET /ordinary-json-document.json HTTP/1.1
Host: example.com
Accept: application/json,*/*;q=0.1

----------------------------------------------------

HTTP/1.0 200 OK
...
Content-Type: application/json


{
  &quot;name&quot;: &quot;Markus Lanthaler&quot;,
  &quot;homepage&quot;: &quot;http://www.markus-lanthaler.com/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/markuslanthaler&quot;
</del>
<pre class="example">GET /ordinary-json-document.json HTTP/1.1
<ins class="diff-chg">Host: example.com
Accept: application/json,*/*;q=0.1
====================================
HTTP/1.0 200 OK
...
Content-Type: application/json
</ins><span class="diff">Link: &lt;http://json-ld.org/contexts/person&gt;; rel=&quot;describedby&quot;; type=&quot;application/ld+json&quot;</span><ins class="diff-chg">
{
  &quot;name&quot;: &quot;Markus Lanthaler&quot;,
  &quot;homepage&quot;: &quot;http://www.markus-lanthaler.com/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/markuslanthaler&quot;
</ins>
}
</pre>
<p class="note">
JSON-LD
documents
<ins class="diff-new">served
with
the
</ins><code><ins class="diff-new">
application/ld+json
</ins></code><ins class="diff-new">
media
type
</ins>
<em class="rfc2119" title="must">
must
</em>
have
all
context
information,
including
references
to
external
contexts,
within
the
body
of
the
document.
</p>
</div>
<del class="diff-old">4.4
Default
Language
JSON-LD
allows
a
default
value
to
use
as
the
language
for
string
value
s.
It
is
commonly
the
case
that
documents
are
written
using
a
single
language.
As
described
in
String
Internationalization
,
a
language-tagged
value
may
be
specified
as
follows:
{
  ...
  &quot;name&quot;:
  {
    &quot;@value&quot;: &quot;花澄&quot;,
    &quot;@language&quot;: &quot;ja&quot;
  }
}
It
is
also
possible
to
apply
a
particular
language
code
to
all
string
value
s
by
setting
the
@language
key
in
the
@context
:
{
  &quot;@context&quot;:
  {
    ...
    &quot;@language&quot;: &quot;ja&quot;
  },
  &quot;name&quot;: ,
  &quot;occupation&quot;:
}
The
example
above
would
generate
a
string
value
for
花澄
and
科学者
and
associate
the
ja
language
code
with
each
value.
It
is
possible
to
override
the
default
language
by
using
the
expanded
form
of
a
value:
{
  &quot;@context&quot;:
  {
    ...
    &quot;@language&quot;: &quot;ja&quot;
  },
  &quot;name&quot;: &quot;花澄&quot;,
  &quot;occupation&quot;:
  {
    &quot;@value&quot;: &quot;Scientist&quot;,
    &quot;@language&quot;: &quot;en&quot;
  }
}
It
is
also
possible
to
override
the
default
language
and
specify
a
plain
value
by
omitting
the
@language
tag
when
expressing
the
expanded
value:
{
  &quot;@context&quot;:
  {
    ...
    &quot;@language&quot;: &quot;ja&quot;
  },
  &quot;name&quot;: &quot;花澄&quot;,
  &quot;occupation&quot;:
  {
    &quot;@value&quot;: &quot;Ninja&quot;
  }
}
Object
properties
that
use
the
expanded
form
are
considered
explicitly
defined.
The
@language
keyword,
when
used
in
the
context
,
must
only
be
applied
to
string
value
s.
That
is,
string
value
s
expressed
in
expanded
form
are
not
affected
by
the
@language
keyword,
when
it
is
used
in
the
context
.
To
clear
the
default
language
for
a
subtree,
@language
can
be
set
to
null
in
a
local
context
as
follows:
{
  &quot;@context&quot;:
  {
    ...
    &quot;@language&quot;: &quot;ja&quot;
  },
  &quot;name&quot;: &quot;花澄&quot;,
  &quot;details&quot;:
  {
    &quot;@context&quot;:
    {
      &quot;@language&quot;: null
    },
    &quot;occupation&quot;: &quot;Ninja&quot;
  }
}
</del>
<div id="expanded-term-definition" class="section">
<h3>
<span class="secno">
4.5
</span>
Expanded
Term
Definition
</h3>
<p>
Within
a
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
definition,
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
<em class="rfc2119" title="may">
may
</em>
be
defined
using
an
expanded
notation
to
allow
for
additional
information
associated
with
the
term
to
be
specified
(see
<ins class="diff-chg">also
</ins><a href="#type-coercion">
Type
Coercion
</a>
and
<a href="#sets-and-lists">
<ins class="diff-chg">Sets
and
</ins>
Lists
</a>
).
</p>
<p>
Instead
of
using
a
string
representation
of
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>,
the
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
<em class="rfc2119" title="may">
may
</em>
be
specified
using
an
object
having
an
<code>
@id
</code>
key.
The
value
of
the
<code>
@id
</code>
key
<em class="rfc2119" title="must">
must
</em>
be
either
a
<a class="tref internalDFN" title="term" href="#dfn-term">
<ins class="diff-new">term
</ins></a>,<ins class="diff-new">
a
</ins>
<a class="tref internalDFN" title="prefix" href="#dfn-prefix">
prefix
</a>:suffix
value,
<ins class="diff-new">or
</ins>
an
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
<ins class="diff-chg">absolute
</ins>
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
Type
information
may
be
specified
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    &quot;foaf&quot;: ,
    &quot;name&quot;: ,
    &quot;homepage&quot;: ,
    &quot;depiction&quot;:
  },
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
    &quot;foaf&quot;: <span class="diff">{ &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/&quot; }</span>,
    &quot;name&quot;: <span class="diff">{ &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot; }</span>,
    &quot;homepage&quot;: <span class="diff">{ &quot;@id&quot;: &quot;foaf:homepage&quot; }</span>,
    &quot;depiction&quot;: <span class="diff">{ &quot;@id&quot;: &quot;foaf:depiction&quot; }</span>
  },
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;depiction&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;
</ins>
}
</pre>
<del class="diff-old">4.6
Automatic
Typing
</del>
<p>
<del class="diff-old">Since
JSON
is
capable
of
expressing
typed
information
such
as
doubles,
integers,
and
boolean
values.
As
demonstrated
below,
JSON-LD
utilizes
that
</del>
<ins class="diff-chg">This
allows
additional
</ins>
information
to
<del class="diff-old">create
typed
value
</del>
<ins class="diff-chg">be
associated
with
the
term.
This
</ins><em class="rfc2119" title="may"><ins class="diff-chg">
may
</ins></em><ins class="diff-chg">
be
used
for
</ins><a href="#type-coercion"><ins class="diff-chg">
Type
Coercion
</ins></a>,<a href="#sets-and-lists"><ins class="diff-chg">
Sets
and
Lists
</ins>
</a>
<del class="diff-old">s:
</del>
<ins class="diff-chg">),
or
to
associate
language
information
with
a
term
as
shown
in
the
following
example:
</ins>
</p>
<del class="diff-old">{
...
  // The following two values are automatically converted to a type of xsd:double
  // and both values are equivalent to each other.
  &quot;measure:cups&quot;: ,
  &quot;measure:cups&quot;: ,
  // The following value is automatically converted to a type of xsd:double as well
  &quot;space:astronomicUnits&quot;: ,
  // The following value is never converted to a language-native type
  &quot;measure:stones&quot;: ,
  // This value is automatically converted to having a type of xsd:integer
  &quot;chem:protons&quot;: ,
  // This value is automatically converted to having a type of xsd:boolean
  &quot;sensor:active&quot;: ,
...
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;: {
    ...
    &quot;ex&quot;: &quot;http://example.com/&quot;,
    &quot;@language&quot;: &quot;ja&quot;,
    &quot;name&quot;: { &quot;@id&quot;: &quot;ex:name&quot;, <span class="diff">&quot;@language&quot;: null</span> },
    &quot;occupation&quot;: { &quot;@id&quot;: &quot;ex:occupation&quot; },
    &quot;occupation_en&quot;: { &quot;@id&quot;: &quot;ex:occupation&quot;, <span class="diff">&quot;@language&quot;: &quot;en&quot;</span> },
    &quot;occupation_de&quot;: { &quot;@id&quot;: &quot;ex:occupation&quot;, <span class="diff">&quot;@language&quot;: &quot;cs&quot;</span> }
  },
</ins>  <span class="diff">&quot;name&quot;: &quot;Yagyū Muneyoshi&quot;,<ins class="diff-chg">
  &quot;occupation&quot;: &quot;忍者&quot;,
  &quot;occupation_en&quot;: &quot;Ninja&quot;,
  &quot;occupation_cs&quot;: &quot;Nindža&quot;,</span>
  ...
</ins>
}
</pre>
<del class="diff-old">When
dealing
</del>
<p>
<ins class="diff-chg">The
example
above
would
associate
</ins><em><ins class="diff-chg">
忍者
</ins></em>
with
<del class="diff-old">a
number
of
modern
programming
languages,
including
JavaScript
ECMA-262,
there
is
no
distinction
between
xsd:decimal
and
xsd:double
values.
That
is,
</del>
the
<del class="diff-old">number
</del>
<ins class="diff-chg">specified
default
language
code
</ins>
<code>
<del class="diff-old">5.3
and
</del>
<ins class="diff-chg">ja
</ins></code>,<em><ins class="diff-chg">
Ninja
</ins></em><ins class="diff-chg">
with
</ins>
the
<del class="diff-old">number
</del>
<ins class="diff-chg">language
code
</ins>
<code>
<del class="diff-old">5.3e0
are
treated
as
if
they
were
the
same.
When
converting
from
JSON-LD
to
a
language-native
format
</del>
<ins class="diff-chg">en
</ins></code>,
and
<del class="diff-old">back,
type
information
is
lost
in
a
number
</del>
<em>
<ins class="diff-chg">Nindža
</ins></em><ins class="diff-chg">
with
the
language
code
</ins><code><ins class="diff-chg">
cs
</ins></code>.<ins class="diff-chg">
The
value
</ins>
of
<del class="diff-old">these
languages.
Thus,
one
could
say
that
</del>
<code>
<del class="diff-old">5.3
is
a
xsd:decimal
and
</del>
<ins class="diff-chg">name
</ins></code>,<em><ins class="diff-chg">
Yagyū
Muneyoshi
</ins></em><ins class="diff-chg">
wouldn't
be
associated
with
any
language
code
since
it
was
reset
in
the
expanded
term
definition.
</ins></p><p><ins class="diff-chg">
Expanded
terms
</ins><em class="rfc2119" title="may"><ins class="diff-chg">
may
</ins></em><ins class="diff-chg">
also
be
defined
using
</ins><a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri"><ins class="diff-chg">
Compact
IRIs
</ins></a><ins class="diff-chg">
or
</ins><a class="tref internalDFN" title="iri" href="#dfn-iri"><ins class="diff-chg">
IRIs
</ins></a><ins class="diff-chg">
as
keys.
If
the
definition
does
not
include
an
</ins>
<code>
<del class="diff-old">5.3e0
</del>
<ins class="diff-chg">@id
</ins>
</code>
<ins class="diff-new">key,
the
expanded
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr>
is
<del class="diff-old">an
xsd:double
in
JSON-LD,
but
when
both
values
are
converted
to
a
language-native
format
</del>
<ins class="diff-chg">determined
by
performing
expansion
of
</ins>
the
<del class="diff-old">type
difference
between
</del>
<ins class="diff-chg">key
within
</ins>
the
<del class="diff-old">two
</del>
<ins class="diff-chg">current
active
context.
</ins></p><p class="note"><ins class="diff-chg">
Although
it
</ins>
is
<del class="diff-old">lost
because
the
machine-level
representation
will
almost
always
be
a
double
.
Implementers
should
be
aware
of
this
potential
round-tripping
issue
between
xsd:decimal
and
xsd:double
.
Specifically
objects
with
a
type
of
xsd:decimal
must
not
be
converted
</del>
<ins class="diff-chg">possible
</ins>
to
<ins class="diff-new">define
</ins>
a
<del class="diff-old">language
native
type.
</del>
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
<ins class="diff-chg">compact
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-chg">
IRI
</ins></abbr></a><ins class="diff-chg">
or
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-chg">
IRI
</ins></abbr><ins class="diff-chg">
to
expand
to
some
other
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-chg">
IRI
</ins></abbr>,<ins class="diff-chg">
such
usage
is
strongly
discouraged.
</ins>
</p>
</div>
<div id="type-coercion" class="section">
<h3>
<span class="secno">
<del class="diff-old">4.7
</del>
<ins class="diff-chg">4.6
</ins>
</span>
Type
Coercion
</h3>
<p>
JSON-LD
supports
the
coercion
of
values
to
particular
data
types.
Type
<dfn title="coercion" id="dfn-coercion">
coercion
</dfn>
allows
someone
deploying
JSON-LD
to
coerce
the
incoming
or
outgoing
types
to
the
proper
data
type
based
on
a
mapping
of
data
type
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
s
to
property
types.
Using
type
coercion,
value
representation
is
preserved
without
requiring
the
data
type
to
be
specified
with
each
usage.
</p>
<p>
Type
coercion
is
specified
within
an
<a href="#expanded-term-definition">
expanded
term
definition
</a>
using
the
<code>
@type
</code>
key.
The
values
of
this
key
represent
type
IRIs
and
<em class="rfc2119" title="must">
must
</em>
take
the
form
of
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>,
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>,
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
or
the
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keyword
</a>
<code>
@id
</code>.
Specifying
<code>
@id
</code>
indicates
that
within
the
body
of
a
JSON-LD
document,
string
values
of
keys
coerced
as
<code>
@id
</code>
are
to
be
interpreted
as
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
s.
</p>
<p>
<a class="tref internalDFN" title="term" href="#dfn-term">
Terms
</a>
or
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
IRIs
</a>
used
as
the
value
of
a
<code>
@type
</code>
key
<em class="rfc2119" title="may">
may
</em>
be
defined
within
the
same
context.
</p>
<p>
The
example
below
demonstrates
how
a
JSON-LD
author
can
coerce
values
to
<a class="tref internalDFN" title="typed_value" href="#dfn-typed_value">
typed
value
</a>
s,
IRIs
and
lists.
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;age&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/age&quot;,
      &quot;@type&quot;: &quot;xsd:integer&quot;
    },
    &quot;homepage&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;,
      &quot;@container&quot;: &quot;@list&quot;
    }
  },
  &quot;name&quot;: &quot;John Smith&quot;,
  &quot;age&quot;: ,
  &quot;homepage&quot;:
  [
    &quot;http://personal.example.org/&quot;,
    &quot;http://work.example.com/jsmith/&quot;
  ]
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;age&quot;:
</ins>    <span class="diff">{<ins class="diff-chg">
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/age&quot;,
      &quot;@type&quot;: &quot;xsd:integer&quot;
    }</span>,
    &quot;homepage&quot;:
</ins>    <span class="diff">{<ins class="diff-chg">
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;,
      &quot;@container&quot;: &quot;@list&quot;
    }</span>
  },
  &quot;name&quot;: &quot;John Smith&quot;,
  &quot;age&quot;: <span class="diff">&quot;41&quot;</span>,
  &quot;homepage&quot;:
</ins>  <span class="diff">[<ins class="diff-chg">
    &quot;http://personal.example.org/&quot;,
    &quot;http://work.example.com/jsmith/&quot;
  ]</span>
</ins>
}
</pre>
<p>
The
example
above
would
generate
the
following
Turtle:
</p>
<del class="diff-old">@prefix xsd: &lt;http://www.w3.org/2001/XMLSchema#&gt; .

[ foaf:name &quot;John Smith&quot;;
  foaf:age  &quot;41&quot;^^xsd:integer;
  foaf:homepage ( &lt;http://personal.example.org/&gt; &lt;http://work.example.com/jsmith/&gt; )
</del>
<pre class="example">@prefix xsd: &lt;http://www.w3.org/2001/XMLSchema#&gt; .
<ins class="diff-chg">[ foaf:name &quot;John Smith&quot;;
  foaf:age  &quot;41&quot;^^xsd:integer;
  foaf:homepage ( &lt;http://personal.example.org/&gt; &lt;http://work.example.com/jsmith/&gt; )
</ins>
]
.
</pre>
<p>
Terms
may
also
be
defined
using
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
absolute
IRIs
</a>
or
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
IRIs
</a>.
This
allows
coercion
rules
to
by
applied
to
keys
which
are
not
represented
as
a
simple
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>.
For
example:
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    ,
    &quot;&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;&quot;,
      &quot;@type&quot;: &quot;xsd:integer&quot;
    },
    &quot;&quot;:
    {
      &quot;@type&quot;: &quot;@id&quot;
    }
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
</ins>    <span class="diff">&quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;</span>,<ins class="diff-chg">
    &quot;<span class="diff">foaf:age</span>&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;&quot;,
      &quot;@type&quot;: &quot;xsd:integer&quot;
    },
    &quot;<span class="diff">foaf:homepage</span>&quot;:
</ins>    <span class="diff">{<ins class="diff-chg">
      &quot;@type&quot;: &quot;@id&quot;
    }</span>
</ins>
}
</pre>
<p>
In
this
case,
the
<code>
@id
</code>
definition
is
optional,
but
if
it
does
exist,
the
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
or
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
is
treated
as
a
term
so
that
the
actual
definition
of
a
<a class="tref internalDFN" title="prefix" href="#dfn-prefix">
prefix
</a>
becomes
unnecessary.
</p>
<p class="note">
<ins class="diff-new">Keys
in
the
context
are
treated
as
</ins><a class="tref internalDFN" title="term" href="#dfn-term"><ins class="diff-new">
terms
</ins></a><ins class="diff-new">
for
the
purpose
of
expansion
and
value
coercion.
This
allows
multiple
representations
for
the
same
expanded
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr>,<ins class="diff-new">
which
may
be
useful
for
establishing
different
type
coercion
rules.
It
also
allows
a
</ins><a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri"><ins class="diff-new">
compact
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr></a><ins class="diff-new">
(or
even
an
absolute
</ins><a class="tref internalDFN" title="iri" href="#dfn-iri"><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr></a><ins class="diff-new">
)
to
be
defined
as
something
else
entirely,
but
this
usage
is
discouraged.
</ins></p><p><ins class="diff-new">
Type
coercion
is
performed
using
the
unexpanded
value
of
the
key,
which
</ins><em class="rfc2119" title="must"><ins class="diff-new">
must
</ins></em><ins class="diff-new">
exactly
match
a
coercion
rule
in
the
</ins><a class="tref internalDFN" title="active_context" href="#dfn-active_context"><ins class="diff-new">
active
context
</ins></a>.</p>
</div>
<div id="iri-expansion-within-a-context" class="section">
<h3>
<span class="secno">
<del class="diff-old">4.8
</del>
<ins class="diff-chg">4.7
</ins>
</span>
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
Expansion
Within
a
Context
</h3>
<p>
To
be
consistent
with
JSON-LD,
in
general,
anywhere
an
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
is
expected,
normal
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
expansion
rules
apply
(see
<a href="#iris">
IRIs
</a>
).
Within
a
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
definition,
this
can
mean
that
terms
defined
within
a
given
context
<em class="rfc2119" title="may">
may
</em>
also
be
used
within
that
context,
as
long
as
there
are
no
circular
dependencies.
For
example,
it
is
common
to
use
the
<code>
xsd
</code>
namespace
when
defining
<a class="tref internalDFN" title="typed_value" href="#dfn-typed_value">
typed
value
</a>
s:
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    ,
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;age&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/age&quot;,
      &quot;@type&quot;:
    },
    &quot;homepage&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    }
  },
  ...
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
</ins>    <span class="diff">&quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;</span>,<ins class="diff-chg">
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;age&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/age&quot;,
      &quot;@type&quot;: <span class="diff">&quot;xsd:integer&quot;</span>
    },
    &quot;homepage&quot;:
    {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    }
  },
  ...
</ins>
}
</pre>
<p>
In
this
example,
the
<code>
xsd
</code>
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
is
defined,
and
used
as
a
<a class="tref internalDFN" title="prefix" href="#dfn-prefix">
prefix
</a>
for
the
<code>
@type
</code>
coercion
of
the
<code>
age
</code>
property.
</p>
<p>
<a class="tref internalDFN" title="term" href="#dfn-term">
Term
</a>
s
<em class="rfc2119" title="may">
may
</em>
also
be
used
when
defining
the
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
of
another
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>:
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    ,
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
    &quot;name&quot;: ,
    &quot;age&quot;:
    {
      &quot;@id&quot;: ,
      &quot;@type&quot;: &quot;xsd:integer&quot;
    },
    &quot;homepage&quot;:
    {
      &quot;@id&quot;: ,
      &quot;@type&quot;: &quot;@id&quot;
    }
  },
  ...
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
</ins>    <span class="diff">&quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;</span>,<ins class="diff-chg">
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
    &quot;name&quot;: <span class="diff">&quot;foaf:name&quot;</span>,
    &quot;age&quot;:
    {
      &quot;@id&quot;: <span class="diff">&quot;foaf:age&quot;</span>,
      &quot;@type&quot;: &quot;xsd:integer&quot;
    },
    &quot;homepage&quot;:
    {
      &quot;@id&quot;: <span class="diff">&quot;foaf:homepage&quot;</span>,
      &quot;@type&quot;: &quot;@id&quot;
    }
  },
  ...
</ins>
}
</pre>
<p>
<ins class="diff-new">Not
only
</ins>
<a class="tref internalDFN" title="term" href="#dfn-term">
<del class="diff-old">Term
</del>
<ins class="diff-chg">term
</ins></a><ins class="diff-chg">
s,
but
also
</ins><a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri"><ins class="diff-chg">
Compact
IRIs
</ins></a><ins class="diff-chg">
and
</ins><a class="tref internalDFN" title="iri" href="#dfn-iri"><ins class="diff-chg">
IRIs
</ins>
</a>
<del class="diff-old">s
</del>
<em class="rfc2119" title="may">
may
</em>
<del class="diff-old">also
</del>
be
used
on
the
left-hand
side
of
a
definition.
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    ,
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
    &quot;name&quot;: &quot;foaf:name&quot;,
    &quot;&quot;:
    {
      &quot;@id&quot;: &quot;foaf:age&quot;,
      &quot;@type&quot;: &quot;xsd:integer&quot;
    },
    &quot;&quot;:
    {
      &quot;@type&quot;: &quot;@id&quot;
    }
  },
  ...
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
</ins>    <span class="diff">&quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;</span>,<ins class="diff-chg">
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
    &quot;name&quot;: &quot;foaf:name&quot;,
    &quot;<span class="diff">foaf:age</span>&quot;:
    {
      &quot;@id&quot;: &quot;foaf:age&quot;,
      &quot;@type&quot;: &quot;xsd:integer&quot;
    },
    &quot;<span class="diff">foaf:homepage</span>&quot;:
</ins>    <span class="diff">{<ins class="diff-chg">
      &quot;@type&quot;: &quot;@id&quot;
    }</span>
  },
  ...
</ins>
}
</pre>
<p>
<del class="diff-old">Note
that
in
</del>
<ins class="diff-chg">In
</ins>
this
example,
the
<a class="tref internalDFN" title="compact_iri" href="#dfn-compact_iri">
compact
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
form
is
used
in
two
different
ways.
The
first
way,
as
shown
with
<code>
foaf:age
</code>
declares
both
the
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
for
the
term
(using
short-form)
as
well
as
the
<code>
@type
</code>
associated
with
the
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>.
The
second
way,
only
declares
the
<code>
@type
</code>
associated
with
the
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>.
In
the
second
case,
the
JSON-LD
processor
will
still
derive
the
full
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
by
looking
up
the
<code>
foaf
</code>
<a class="tref internalDFN" title="prefix" href="#dfn-prefix">
prefix
</a>
in
the
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
for
<code>
foaf:homepage
</code>.
</p>
<p>
<del class="diff-old">Full
</del>
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
<ins class="diff-chg">Absolute
</ins>
IRIs
</a>
<em class="rfc2119" title="may">
may
</em>
also
be
used
on
the
left-hand
side
of
a
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>:
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;,
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
    &quot;name&quot;: &quot;foaf:name&quot;,
    &quot;foaf:age&quot;:
    {
      &quot;@id&quot;: &quot;foaf:age&quot;,
      &quot;@type&quot;: &quot;xsd:integer&quot;
    },
    &quot;&quot;:
    {
      &quot;@type&quot;: &quot;@id&quot;
    }
  },
  ...
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;,
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;,
    &quot;name&quot;: &quot;foaf:name&quot;,
    &quot;foaf:age&quot;:
    {
      &quot;@id&quot;: &quot;foaf:age&quot;,
      &quot;@type&quot;: &quot;xsd:integer&quot;
    },
    &quot;<span class="diff">http://xmlns.com/foaf/0.1/homepage</span>&quot;:
    {
      &quot;@type&quot;: &quot;@id&quot;
    }
  },
  ...
</ins>
}
</pre>
<p>
<del class="diff-old">Note
that
in
</del>
<ins class="diff-chg">In
</ins>
order
for
the
<del class="diff-old">full
</del>
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
<ins class="diff-chg">absolute
</ins>
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
to
match
above,
the
<del class="diff-old">full
</del>
<a class="tref internalDFN" title="absolute_iri" href="#dfn-absolute_iri">
<ins class="diff-chg">absolute
</ins>
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
<em class="rfc2119" title="must">
must
</em>
also
be
used
in
the
JSON-LD
document.
Also
note
that
<code>
foaf:homepage
</code>
will
not
use
the
<code>
{
&quot;@type&quot;:
&quot;@id&quot;
}
</code>
declaration
because
<code>
foaf:homepage
</code>
is
not
the
same
as
<code>
http://xmlns.com/foaf/0.1/homepage
</code>.
That
is,
a
JSON-LD
processor
will
use
direct
string
comparison
when
looking
up
<a class="tref internalDFN" title="term" href="#dfn-term">
term
</a>
s
in
a
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
before
it
applies
the
<a class="tref internalDFN" title="prefix" href="#dfn-prefix">
prefix
</a>
lookup
mechanism.
</p>
<p>
The
only
exception
for
using
terms
in
the
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
is
that
they
<em class="rfc2119" title="must not">
must
not
</em>
be
used
in
a
circular
manner.
That
is,
a
definition
of
<em>
term-1
</em>
<em class="rfc2119" title="must not">
must
not
</em>
depend
on
the
definition
of
<em>
term-2
</em>
if
<em>
term-2
</em>
also
depends
on
<em>
term-1
</em>.
For
example,
the
following
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
definition
is
illegal:
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    &quot;term1&quot;: &quot;term2:foo&quot;,
    &quot;term2&quot;: &quot;term1:bar&quot;
  },
  ...
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
</ins>    <span class="diff">&quot;term1&quot;: &quot;term2:foo&quot;,<ins class="diff-chg">
    &quot;term2&quot;: &quot;term1:bar&quot;</span>
  },
  ...
</ins>
}
</pre>
</div>
<div id="embedding" class="section">
<h3>
<span class="secno">
<del class="diff-old">4.9
</del>
<ins class="diff-chg">4.8
</ins>
</span>
Embedding
</h3>
<p>
Object
<dfn title="embedding" id="dfn-embedding">
embedding
</dfn>
is
a
JSON-LD
feature
that
allows
an
author
to
use
the
definition
of
JSON-LD
objects
as
<a class="tref internalDFN" title="property" href="#dfn-property">
property
</a>
values.
This
is
a
commonly
used
mechanism
for
creating
a
parent-child
relationship
between
two
<a class="tref internalDFN" title="subject" href="#dfn-subject">
subject
</a>
s.
</p>
<p>
The
example
shows
two
subjects
related
by
a
property
from
the
first
subject:
</p>
<del class="diff-old">  {
...
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;&quot;:
  {
    &quot;&quot;,
    &quot;&quot;,
  }
...
</del>
  <pre class="example">{
<ins class="diff-chg">...
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;<span class="diff">knows</span>&quot;:
  {
    &quot;<span class="diff">@type</span>&quot;: &quot;<span class="diff">Person</span>&quot;,
    &quot;<span class="diff">name</span>&quot;: &quot;<span class="diff">Gregg Kellogg</span>&quot;,
  }
...
</ins>
}
</pre>
<p>
An
object
definition,
like
the
one
used
above,
<em class="rfc2119" title="may">
may
</em>
be
used
as
a
JSON
value
at
any
point
in
JSON-LD.
</p>
</div>
<div id="named-graphs" class="section">
<h3>
<span class="secno">
<ins class="diff-new">4.9
</ins></span><ins class="diff-new">
Named
Graphs
</ins></h3><p><ins class="diff-new">
The
</ins><code><ins class="diff-new">
@graph
</ins></code><a class="tref internalDFN" title="keyword" href="#dfn-keyword"><ins class="diff-new">
keyword
</ins></a><ins class="diff-new">
is
used
to
identify
a
set
of
JSON-LD
object
definitions
that
may
not
be
directly
related
through
a
property,
or
where
</ins><a class="tref internalDFN" title="embedding" href="#dfn-embedding"><ins class="diff-new">
embedding
</ins></a><ins class="diff-new">
is
not
appropriate.
For
example:
</ins></p>  <pre class="example">{<ins class="diff-new">
  &quot;@context&quot;: ...,
  &quot;<span class="diff">@graph</span>&quot;:
  [
    {
      &quot;@id&quot;: &quot;http://manu.sporny.org/i/public&quot;,
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;name&quot;: &quot;Manu Sporny&quot;,
      &quot;knows&quot; &quot;http://greggkellogg.net/foaf#me&quot;
    },
    {
      &quot;@id&quot;: &quot;http://greggkellogg.net/foaf#me&quot;,
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;name&quot;: &quot;Gregg Kellogg&quot;,
      &quot;knows&quot; &quot;http://manu.sporny.org/i/public&quot;
    }
  ]
}
</ins></pre><p><ins class="diff-new">
In
this
case,
embedding
doesn't
work
as
each
JSON-LD
object
references
the
other.
Using
the
</ins><code><ins class="diff-new">
@graph
</ins></code><a class="tref internalDFN" title="keyword" href="#dfn-keyword"><ins class="diff-new">
keyword
</ins></a><ins class="diff-new">
allows
multiple
resources
to
be
defined
within
an
</ins><a class="tref internalDFN" title="array" href="#dfn-array"><ins class="diff-new">
array
</ins></a>,<ins class="diff-new">
and
allows
the
use
of
a
shared
</ins><a class="tref internalDFN" title="context" href="#dfn-context"><ins class="diff-new">
context
</ins></a>.<ins class="diff-new">
This
is
equivalent
to
using
multiple
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-new">
JSON
object
</ins></a><ins class="diff-new">
definitions
in
array
and
defining
the
</ins><code><ins class="diff-new">
@context
</ins></code><ins class="diff-new">
within
each
object:
</ins></p>  <pre class="example"><span class="diff">[</span><ins class="diff-new">
  {
</ins>    <span class="diff">&quot;@context&quot;: ...,</span><ins class="diff-new">
    &quot;@id&quot;: &quot;http://manu.sporny.org/i/public&quot;,
    &quot;@type&quot;: &quot;foaf:Person&quot;,
    &quot;name&quot;: &quot;Manu Sporny&quot;,
    &quot;knows&quot; &quot;http://greggkellogg.net/foaf#me&quot;
  },
  {
</ins>    <span class="diff">&quot;@context&quot;: ...,</span><ins class="diff-new">
    &quot;@id&quot;: &quot;http://greggkellogg.net/foaf#me&quot;,
    &quot;@type&quot;: &quot;foaf:Person&quot;,
    &quot;name&quot;: &quot;Gregg Kellogg&quot;,
    &quot;knows&quot; &quot;http://manu.sporny.org/i/public&quot;
  }
</ins><span class="diff"><ins class="diff-new">
]
</ins></span></pre><p><ins class="diff-new">
The
</ins><code><ins class="diff-new">
@graph
</ins></code><a class="tref internalDFN" title="keyword" href="#dfn-keyword"><ins class="diff-new">
keyword
</ins></a><ins class="diff-new">
takes
on
additional
meaning
when
it
is
used
along
with
other
properties,
or
is
used
within
an
embedded
JSON-LD
object.
In
this
case,
the
set
of
</ins><a class="tref internalDFN" title="subject_definition" href="#dfn-subject_definition"><ins class="diff-new">
subject
definitions
</ins></a>,<ins class="diff-new">
or
</ins><a class="tref internalDFN" title="subject_reference" href="#dfn-subject_reference"><ins class="diff-new">
subject
references
</ins></a><ins class="diff-new">
contained
within
a
</ins><code><ins class="diff-new">
@graph
</ins></code><ins class="diff-new">
is
given
a
</ins><em><ins class="diff-new">
name
</ins></em>,<ins class="diff-new">
based
on
the
label
of
the
JSON-LD
object
containing
a
</ins><code><ins class="diff-new">
@graph
</ins></code><ins class="diff-new">
property,
either
an
</ins><a class="tref internalDFN" title="iri" href="#dfn-iri"><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr></a>,<ins class="diff-new">
or
an
</ins><a class="tref internalDFN" title="unlabeled_node" href="#dfn-unlabeled_node"><ins class="diff-new">
unlabeled
node
</ins></a>.<ins class="diff-new">
This
allows
statements
to
be
made
about
an
entire
</ins><a class="tref internalDFN" title="linked_data_graph" href="#dfn-linked_data_graph"><ins class="diff-new">
linked
data
graph
</ins></a>,<ins class="diff-new">
rather
than
just
a
single
JSON-LD
object.
</ins></p>  <pre class="example">{<ins class="diff-new">
  &quot;@context&quot;: ...,
</ins>  <span class="diff">&quot;@id&quot;: &quot;http://example.org/linked-data-graph&quot;,<ins class="diff-new">
  &quot;asOf&quot;: { &quot;@value&quot;: &quot;2012-04-09&quot;, &quot;@type&quot;: &quot;xsd:date&quot; },
  &quot;@graph&quot;:</span>
  [
    {
      &quot;@id&quot;: &quot;http://manu.sporny.org/i/public&quot;,
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;name&quot;: &quot;Manu Sporny&quot;,
      &quot;knows&quot; &quot;http://greggkellogg.net/foaf#me&quot;
    },
    {
      &quot;@id&quot;: &quot;http://greggkellogg.net/foaf#me&quot;,
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;name&quot;: &quot;Gregg Kellogg&quot;,
      &quot;knows&quot; &quot;http://manu.sporny.org/i/public&quot;
    },
    &quot;http://www.markus-lanthaler.com/&quot;
  ]
}
</ins></pre><p><ins class="diff-new">
This
example
says
that
there
is
a
</ins><a class="tref internalDFN" title="linked_data_graph" href="#dfn-linked_data_graph"><ins class="diff-new">
linked
data
graph
</ins></a><ins class="diff-new">
identified
by
</ins><code><ins class="diff-new">
http://example.org/linked-data-graph
</ins></code><ins class="diff-new">
which
is
composed
of
the
statements
about
Manu
and
Gregg
and
a
reference
to
another
</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
IRI
</ins></abbr>,<ins class="diff-new">
which
could
make
statements
about
Markus.
Additionally,
there
is
information
about
the
graph
itself,
which
indicates
a
time
at
which
this
information
as
asserted
to
be
true.
</ins></p></div>
<div id="identifying-unlabeled-nodes" class="section">
<h3>
<span class="secno">
4.10
</span>
Identifying
Unlabeled
Nodes
</h3>
<p>
At
times,
it
becomes
necessary
to
be
able
to
express
information
without
being
able
to
specify
the
subject.
Typically,
this
type
of
node
is
called
an
<a class="tref internalDFN" title="unlabeled_node" href="#dfn-unlabeled_node">
unlabeled
node
</a>
or
a
blank
node.
In
JSON-LD,
<a class="tref internalDFN" title="unlabeled_node" href="#dfn-unlabeled_node">
unlabeled
node
</a>
identifiers
are
automatically
created
if
a
subject
is
not
specified
using
the
<code>
@id
</code>
<del class="diff-old">keyword.
</del>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
<ins class="diff-chg">keyword
</ins></a>.
However,
authors
may
provide
identifiers
for
unlabeled
nodes
by
using
the
special
<code>
_
</code>
(underscore)
<a class="tref internalDFN" title="prefix" href="#dfn-prefix">
prefix
</a>.
This
allows
to
reference
the
node
locally
within
the
document
but
not
in
an
external
document.
</p>
<del class="diff-old">{
...
  &quot;@id&quot;: &quot;&quot;,
...
</del>
<pre class="example">{
<ins class="diff-chg">...
  &quot;@id&quot;: &quot;<span class="diff">_:foo</span>&quot;,
...
</ins>
}
</pre>
<p>
The
example
above
would
set
the
subject
to
<code>
_:foo
</code>,
which
can
then
be
used
later
on
in
the
JSON-LD
markup
to
refer
back
to
the
<a class="tref internalDFN" title="unlabeled_node" href="#dfn-unlabeled_node">
unlabeled
<del class="diff-old">node.
</del>
<ins class="diff-chg">node
</ins></a>.
This
practice,
however,
is
usually
frowned
upon
when
generating
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>.
If
a
developer
finds
that
they
refer
to
the
unlabeled
node
more
than
once,
they
should
consider
naming
the
node
using
a
<del class="diff-old">resolve-able
</del>
<ins class="diff-chg">de-referenceable
</ins>
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
</p>
</div>
<div id="aliasing-keywords" class="section">
<h3>
<span class="secno">
4.11
</span>
Aliasing
Keywords
</h3>
<p>
JSON-LD
allows
all
of
the
syntax
<del class="diff-old">keywords,
</del>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
<ins class="diff-chg">keywords
</ins></a>,
except
for
<code>
@context
</code>,
to
be
aliased.
This
feature
allows
more
legacy
JSON
content
to
be
supported
by
JSON-LD.
It
also
allows
developers
to
design
domain-specific
implementations
using
only
the
JSON-LD
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>.
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
     ,
     ,
     &quot;name&quot;: &quot;http://schema.org/name&quot;
  },
  &quot;url&quot;: &quot;http://example.com/about#gregg&quot;,
  &quot;a&quot;: &quot;http://schema.org/Person&quot;,
  &quot;name&quot;: &quot;Gregg Kellogg&quot;
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
</ins>     <span class="diff">&quot;url&quot;: &quot;@id&quot;</span>,     <span class="diff">&quot;a&quot;: &quot;@type&quot;</span>,<ins class="diff-chg">
     &quot;name&quot;: &quot;http://schema.org/name&quot;
  },
  &quot;url&quot;: &quot;http://example.com/about#gregg&quot;,
  &quot;a&quot;: &quot;http://schema.org/Person&quot;,
  &quot;name&quot;: &quot;Gregg Kellogg&quot;
</ins>
}
</pre>
<p>
In
the
example
above,
the
<code>
@id
</code>
and
<code>
@type
</code>
<a class="tref internalDFN" title="keyword" href="#dfn-keyword">
keywords
</a>
have
been
given
the
aliases
<strong>
url
</strong>
and
<strong>
a
</strong>,
respectively.
</p>
</div>
<div id="expansion" class="section">
<h3>
<span class="secno">
4.12
</span>
Expansion
</h3>
<p>
The
JSON-LD
API
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-JSON-LD-API">
JSON-LD-API
</a>
</cite>
]
defines
an
method
for
<em>
expanding
</em>
a
JSON-LD
document.
Expansion
is
the
process
of
taking
a
JSON-LD
document
and
applying
a
context
such
that
all
<del class="diff-old">IRI
,
</del>
<ins class="diff-chg">IRIs,
</ins>
datatypes,
and
literal
values
are
expanded
so
that
the
context
is
no
longer
necessary.
JSON-LD
document
expansion
is
typically
used
as
a
part
of
<a href="#framing">
Framing
</a>.
</p>
<p>
For
example,
assume
the
following
JSON-LD
input
document:
</p>
<del class="diff-old">{
   &quot;@context&quot;:
   {
      &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
      &quot;homepage&quot;: {
        &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
        &quot;@type&quot;, &quot;@id&quot;
      }
   },
   &quot;name&quot;: &quot;Manu Sporny&quot;,
   &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;
</del>
<pre class="example">{
<ins class="diff-chg">   &quot;@context&quot;:
   {
      &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
      &quot;homepage&quot;: {
        &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
        &quot;@type&quot;, &quot;@id&quot;
      }
   },
   &quot;name&quot;: &quot;Manu Sporny&quot;,
   &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;
</ins>
}
</pre>
<p>
Running
the
JSON-LD
Expansion
algorithm
against
the
JSON-LD
input
document
provided
above
would
result
in
the
following
output:
</p>
<del class="diff-old">{
   &quot;http://xmlns.com/foaf/0.1/name&quot;: &quot;Manu Sporny&quot;,
   &quot;http://xmlns.com/foaf/0.1/homepage&quot;: {
      &quot;@id&quot;: &quot;http://manu.sporny.org/&quot;
   }
}
</del>
<pre class="example">[
<ins class="diff-chg">  {
    &quot;http://xmlns.com/foaf/0.1/name&quot;: [ &quot;Manu Sporny&quot; ],
    &quot;http://xmlns.com/foaf/0.1/homepage&quot;: [
      {
       &quot;@id&quot;: &quot;http://manu.sporny.org/&quot;
      }
    ]
  }
]
</ins>
</pre>
</div>
<div id="compaction" class="section">
<h3>
<span class="secno">
4.13
</span>
Compaction
</h3>
<p>
The
JSON-LD
API
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-JSON-LD-API">
JSON-LD-API
</a>
</cite>
]
defines
<del class="diff-old">an
</del>
<ins class="diff-chg">a
</ins>
method
for
<em>
compacting
</em>
a
JSON-LD
document.
Compaction
is
the
process
of
taking
a
JSON-LD
document
and
applying
a
context
such
that
the
most
compact
form
of
the
document
is
generated.
JSON
is
typically
expressed
in
a
very
compact,
key-value
format.
That
is,
full
IRIs
are
rarely
used
as
keys.
At
times,
a
JSON-LD
document
may
be
received
that
is
not
in
its
most
compact
form.
JSON-LD,
via
the
API,
provides
a
way
to
compact
a
JSON-LD
document.
</p>
<p>
For
example,
assume
the
following
JSON-LD
input
document:
</p>
<del class="diff-old">{
  &quot;http://xmlns.com/foaf/0.1/name&quot;: &quot;Manu Sporny&quot;,
  &quot;http://xmlns.com/foaf/0.1/homepage&quot;: {
    &quot;@id&quot;: &quot;http://manu.sporny.org/&quot;
  }
}
</del>
<pre class="example">[
<ins class="diff-chg">  {
    &quot;http://xmlns.com/foaf/0.1/name&quot;: [ &quot;Manu Sporny&quot; ],
    &quot;http://xmlns.com/foaf/0.1/homepage&quot;: [
      {
       &quot;@id&quot;: &quot;http://manu.sporny.org/&quot;
      }
    ]
  }
]
</ins>
</pre>
<p>
Additionally,
assume
the
following
developer-supplied
JSON-LD
context:
</p>
<del class="diff-old">{
  &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
  &quot;homepage&quot;: {
    &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
    &quot;@type&quot;: &quot;@id&quot;
  }
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;: {
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;homepage&quot;: {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    }
  }
</ins>
}
</pre>
<p>
Running
the
JSON-LD
Compaction
algorithm
given
the
context
supplied
above
against
the
JSON-LD
input
document
provided
above
would
result
in
the
following
output:
</p>
<del class="diff-old">{
  &quot;@context&quot;: {
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;homepage&quot;: {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    }
  },
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;: {
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;homepage&quot;: {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    }
  },
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;
</ins>
}
</pre>
<p>
The
compaction
algorithm
also
enables
the
developer
to
map
any
expanded
format
into
an
application-specific
compacted
format.
While
the
context
provided
above
mapped
<code>
http://xmlns.com/foaf/0.1/name
</code>
to
<strong>
name
</strong>,
it
could
have
also
mapped
it
to
any
arbitrary
string
provided
by
the
developer.
</p>
</div>
<div id="framing" class="section">
<h3>
<span class="secno">
4.14
</span>
Framing
</h3>
<p>
The
JSON-LD
API
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-JSON-LD-API">
JSON-LD-API
</a>
</cite>
]
defines
an
method
for
<em>
framing
</em>
a
JSON-LD
document.
This
allows
developers
to
query
by
example
and
force
a
specific
tree
layout
to
a
JSON-LD
document.
</p>
<p>
A
JSON-LD
document
is
a
representation
of
a
directed
graph.
A
single
directed
graph
can
have
many
different
serializations,
each
expressing
exactly
the
same
information.
Developers
typically
work
with
trees,
represented
as
<a class="tref internalDFN" title="json_object" href="#dfn-json_object">
JSON
object
</a>
s.
While
mapping
a
graph
to
a
tree
can
be
done,
the
layout
of
the
end
result
must
be
specified
in
advance.
A
<dfn title="frame" id="dfn-frame">
Frame
</dfn>
can
be
used
by
a
developer
on
a
JSON-LD
document
to
specify
a
deterministic
layout
for
a
graph.
</p>
<p>
Framing
is
the
process
of
taking
a
JSON-LD
document,
which
expresses
a
graph
of
information,
and
applying
a
specific
graph
layout
(called
a
<a class="tref internalDFN" title="frame" href="#dfn-frame">
Frame
</a>
).
</p>
<p>
The
JSON-LD
document
below
expresses
a
library,
a
book
and
a
chapter:
</p>
<del class="diff-old">{
  &quot;@context&quot;: {
    &quot;Book&quot;:         &quot;http://example.org/vocab#Book&quot;,
    &quot;Chapter&quot;:      &quot;http://example.org/vocab#Chapter&quot;,
    &quot;contains&quot;:     {
      &quot;@id&quot;: &quot;http://example.org/vocab#contains&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
    &quot;creator&quot;:      &quot;http://purl.org/dc/terms/creator&quot;,
    &quot;description&quot;:  &quot;http://purl.org/dc/terms/description&quot;,
    &quot;Library&quot;:      &quot;http://example.org/vocab#Library&quot;,
    &quot;title&quot;:        &quot;http://purl.org/dc/terms/title&quot;
  },
  &quot;@id&quot;:
  [{
    &quot;@id&quot;: &quot;http://example.com/library&quot;,
    &quot;@type&quot;: &quot;Library&quot;,
    &quot;contains&quot;: &quot;http://example.org/library/the-republic&quot;
  },
  {
    &quot;@id&quot;: &quot;http://example.org/library/the-republic&quot;,
    &quot;@type&quot;: &quot;Book&quot;,
    &quot;creator&quot;: &quot;Plato&quot;,
    &quot;title&quot;: &quot;The Republic&quot;,
    &quot;contains&quot;: &quot;http://example.org/library/the-republic#introduction&quot;
  },
  {
    &quot;@id&quot;: &quot;http://example.org/library/the-republic#introduction&quot;,
    &quot;@type&quot;: &quot;Chapter&quot;,
    &quot;description&quot;: &quot;An introductory chapter on The Republic.&quot;,
    &quot;title&quot;: &quot;The Introduction&quot;
  }]
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;: {
    &quot;Book&quot;:         &quot;http://example.org/vocab#Book&quot;,
    &quot;Chapter&quot;:      &quot;http://example.org/vocab#Chapter&quot;,
    &quot;contains&quot;:     {
      &quot;@id&quot;: &quot;http://example.org/vocab#contains&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
    &quot;creator&quot;:      &quot;http://purl.org/dc/terms/creator&quot;,
    &quot;description&quot;:  &quot;http://purl.org/dc/terms/description&quot;,
    &quot;Library&quot;:      &quot;http://example.org/vocab#Library&quot;,
    &quot;title&quot;:        &quot;http://purl.org/dc/terms/title&quot;
  },
  &quot;@graph&quot;:
  [{
    &quot;@id&quot;: &quot;http://example.com/library&quot;,
    &quot;@type&quot;: &quot;Library&quot;,
    &quot;contains&quot;: &quot;http://example.org/library/the-republic&quot;
  },
  {
    &quot;@id&quot;: &quot;http://example.org/library/the-republic&quot;,
    &quot;@type&quot;: &quot;Book&quot;,
    &quot;creator&quot;: &quot;Plato&quot;,
    &quot;title&quot;: &quot;The Republic&quot;,
    &quot;contains&quot;: &quot;http://example.org/library/the-republic#introduction&quot;
  },
  {
    &quot;@id&quot;: &quot;http://example.org/library/the-republic#introduction&quot;,
    &quot;@type&quot;: &quot;Chapter&quot;,
    &quot;description&quot;: &quot;An introductory chapter on The Republic.&quot;,
    &quot;title&quot;: &quot;The Introduction&quot;
  }]
</ins>
}
</pre>
<p>
Developers
typically
like
to
operate
on
items
in
a
hierarchical,
tree-based
fashion.
Ideally,
a
developer
would
want
the
data
above
sorted
into
top-level
libraries,
then
the
books
that
are
contained
in
each
library,
and
then
the
chapters
contained
in
each
book.
To
achieve
that
layout,
the
developer
can
define
the
following
<a class="tref internalDFN" title="frame" href="#dfn-frame">
frame
</a>:
</p>
<del class="diff-old">{
  &quot;@context&quot;: {
    &quot;Book&quot;:         &quot;http://example.org/vocab#Book&quot;,
    &quot;Chapter&quot;:      &quot;http://example.org/vocab#Chapter&quot;,
    &quot;contains&quot;:     &quot;http://example.org/vocab#contains&quot;,
    &quot;creator&quot;:      &quot;http://purl.org/dc/terms/creator&quot;
    &quot;description&quot;:  &quot;http://purl.org/dc/terms/description&quot;
    &quot;Library&quot;:      &quot;http://example.org/vocab#Library&quot;,
    &quot;title&quot;:        &quot;http://purl.org/dc/terms/title&quot;
  },
  &quot;@type&quot;: &quot;Library&quot;,
  &quot;contains&quot;: {
    &quot;@type&quot;: &quot;Book&quot;,
    &quot;contains&quot;: {
      &quot;@type&quot;: &quot;Chapter&quot;
    }
  }
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;: {
    &quot;Book&quot;:         &quot;http://example.org/vocab#Book&quot;,
    &quot;Chapter&quot;:      &quot;http://example.org/vocab#Chapter&quot;,
    &quot;contains&quot;:     &quot;http://example.org/vocab#contains&quot;,
    &quot;creator&quot;:      &quot;http://purl.org/dc/terms/creator&quot;,
    &quot;description&quot;:  &quot;http://purl.org/dc/terms/description&quot;,
    &quot;Library&quot;:      &quot;http://example.org/vocab#Library&quot;,
    &quot;title&quot;:        &quot;http://purl.org/dc/terms/title&quot;
  },
  &quot;@type&quot;: &quot;Library&quot;,
  &quot;contains&quot;: {
    &quot;@type&quot;: &quot;Book&quot;,
    &quot;contains&quot;: {
      &quot;@type&quot;: &quot;Chapter&quot;
    }
  }
</ins>
}
</pre>
<p>
When
the
framing
algorithm
is
run
against
the
previously
defined
JSON-LD
document,
paired
with
the
<a class="tref internalDFN" title="frame" href="#dfn-frame">
frame
</a>
above,
the
following
JSON-LD
document
is
the
end
result:
</p>
<del class="diff-old">{
  &quot;@context&quot;: {
    &quot;Book&quot;:         &quot;http://example.org/vocab#Book&quot;,
    &quot;Chapter&quot;:      &quot;http://example.org/vocab#Chapter&quot;,
    &quot;contains&quot;:     &quot;http://example.org/vocab#contains&quot;,
    &quot;creator&quot;:      &quot;http://purl.org/dc/terms/creator&quot;
    &quot;description&quot;:  &quot;http://purl.org/dc/terms/description&quot;
    &quot;Library&quot;:      &quot;http://example.org/vocab#Library&quot;,
    &quot;title&quot;:        &quot;http://purl.org/dc/terms/title&quot;
  },
  &quot;@id&quot;: &quot;http://example.org/library&quot;,
  &quot;@type&quot;: &quot;Library&quot;,
  &quot;contains&quot;: {

    &quot;@type&quot;: &quot;Book&quot;,


    &quot;contains&quot;: {

      &quot;@type&quot;: &quot;Chapter&quot;,


    },
  },
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;: {
    &quot;Book&quot;:         &quot;http://example.org/vocab#Book&quot;,
    &quot;Chapter&quot;:      &quot;http://example.org/vocab#Chapter&quot;,
    &quot;contains&quot;:     &quot;http://example.org/vocab#contains&quot;,
    &quot;creator&quot;:      &quot;http://purl.org/dc/terms/creator&quot;
    &quot;description&quot;:  &quot;http://purl.org/dc/terms/description&quot;
    &quot;Library&quot;:      &quot;http://example.org/vocab#Library&quot;,
    &quot;title&quot;:        &quot;http://purl.org/dc/terms/title&quot;
  },
  &quot;@id&quot;: &quot;http://example.org/library&quot;,
  &quot;@type&quot;: &quot;Library&quot;,
  &quot;contains&quot;: {
</ins>    <span class="diff">&quot;@id&quot;: &quot;http://example.org/library/the-republic&quot;,</span><ins class="diff-chg">
    &quot;@type&quot;: &quot;Book&quot;,
</ins>    <span class="diff">&quot;creator&quot;: &quot;Plato&quot;,</span>    <span class="diff">&quot;title&quot;: &quot;The Republic&quot;,</span><ins class="diff-chg">
    &quot;contains&quot;: {
</ins>      <span class="diff">&quot;@id&quot;: &quot;http://example.org/library/the-republic#introduction&quot;,</span><ins class="diff-chg">
      &quot;@type&quot;: &quot;Chapter&quot;,
</ins>      <span class="diff">&quot;description&quot;: &quot;An introductory chapter on The Republic.&quot;,</span>      <span class="diff">&quot;title&quot;: &quot;The Introduction&quot;</span><ins class="diff-chg">
    },
  },
</ins>
}
</pre>
<div id="framing-operators" class="section">
<h4>
<span class="secno">
<del class="diff-old">4.15
</del>
<ins class="diff-chg">4.14.1
</ins>
</span>
<del class="diff-old">Normalization
</del>
<ins class="diff-chg">Framing
Operators
</ins></h4>
<p>
<del class="diff-old">The
JSON-LD
API
[
JSON-LD-API
</del>
<ins class="diff-chg">A
</ins><a class="tref internalDFN" title="frame" href="#dfn-frame"><ins class="diff-chg">
frame
</ins>
</a>
<del class="diff-old">]
defines
an
method
for
normalizing
a
JSON-LD
document.
Normalization
</del>
is
<del class="diff-old">the
process
of
performing
a
deterministic
transformation
on
</del>
a
JSON-LD
document
<del class="diff-old">resulting
in
a
normalized
representation.
Normalization
is
useful
when
comparing
two
graphs
</del>
<ins class="diff-chg">with
some
extra
syntactic
elements
used
to
match
</ins>
against
<del class="diff-old">one
another,
when
generating
a
detailed
list
</del>
<ins class="diff-chg">parts
</ins>
of
<del class="diff-old">differences
between
two
graphs,
and
when
generating
a
cryptographic
digital
signature
for
information
contained
in
</del>
<ins class="diff-chg">an
input
document.
These
operators
work
by
matching
on
elements
of
</ins><a class="tref internalDFN" title="subject_definition" href="#dfn-subject_definition"><ins class="diff-chg">
subject
definitions
</ins></a><ins class="diff-chg">
comprising
the
document.
</ins></p><dl><dt><ins class="diff-chg">
Type
Matching
</ins></dt><dd><ins class="diff-chg">
A
</ins><a class="tref internalDFN" title="frame" href="#dfn-frame"><ins class="diff-chg">
frame
</ins></a><ins class="diff-chg">
including
</ins>
a
<del class="diff-old">graph
</del>
<code>
<ins class="diff-chg">@type
</ins></code><ins class="diff-chg">
with
one
</ins>
or
<del class="diff-old">when
generating
</del>
<ins class="diff-chg">more
values
matches
any
</ins><a class="tref internalDFN" title="subject_definition" href="#dfn-subject_definition"><ins class="diff-chg">
subject
definition
</ins></a><ins class="diff-chg">
having
</ins>
a
<del class="diff-old">hash
of
</del>
<code>
<ins class="diff-chg">@type
</ins></code><ins class="diff-chg">
property
that
includes
</ins>
the
<del class="diff-old">information
contained
in
</del>
<ins class="diff-chg">specified
type.
</ins></dd><dt><ins class="diff-chg">
Type
Wildcard
</ins></dt><dd><ins class="diff-chg">
A
</ins><a class="tref internalDFN" title="frame" href="#dfn-frame"><ins class="diff-chg">
frame
</ins></a><ins class="diff-chg">
including
</ins>
a
<del class="diff-old">graph.
The
example
below
is
</del>
<code>
<ins class="diff-chg">@type
</ins></code><ins class="diff-chg">
having
only
</ins>
an
<del class="diff-old">un-normalized
JSON-LD
document:
{
  &quot;@context&quot;: {
    &quot;name&quot;: &quot;http://xmlns.com/foaf/0.1/name&quot;,
    &quot;homepage&quot;: {
      &quot;@id&quot;: &quot;http://xmlns.com/foaf/0.1/homepage&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
    &quot;xsd&quot;: &quot;http://www.w3.org/2001/XMLSchema#&quot;
  },
  &quot;name&quot;: &quot;Manu Sporny&quot;,
  &quot;homepage&quot;: &quot;http://manu.sporny.org/&quot;
}
The
example
below
is
the
normalized
form
of
the
JSON-LD
document
above:
[{
  &quot;@id&quot;: &quot;_:c14n0&quot;,
  &quot;http://xmlns.com/foaf/0.1/homepage&quot;: {
    &quot;@id&quot;: &quot;http://manu.sporny.org/&quot;
  },
  &quot;http://xmlns.com/foaf/0.1/name&quot;: &quot;Manu Sporny&quot;
}]
Notice
how
all
of
the
term
</del>
<ins class="diff-chg">empty
</ins><a class="tref internalDFN" title="json_object" href="#dfn-json_object"><ins class="diff-chg">
JSON
object
</ins>
</a>
<del class="diff-old">s
have
been
expanded
and
sorted
in
alphabetical
order.
Also,
notice
how
the
</del>
<ins class="diff-chg">matches
any
</ins><a class="tref internalDFN" title="subject_definition" href="#dfn-subject_definition">
subject
<ins class="diff-new">definition
</ins>
</a>
<del class="diff-old">has
been
labeled
</del>
<ins class="diff-chg">having
a
</ins><code><ins class="diff-chg">
@type
</ins></code><ins class="diff-chg">
property
</ins>
with
<ins class="diff-new">any
value.
</ins></dd><dt><ins class="diff-new">
Duck
Typing
</ins></dt><dd><ins class="diff-new">
A
</ins><a class="tref internalDFN" title="frame" href="#dfn-frame"><ins class="diff-new">
frame
</ins></a><ins class="diff-new">
without
</ins>
a
<del class="diff-old">named
unlabeled
node
.
Normalization
ensures
that
</del>
<code>
<ins class="diff-chg">@type
</ins></code><ins class="diff-chg">
definition
but
with
other
non-
</ins><a class="tref internalDFN" title="keyword" href="#dfn-keyword"><ins class="diff-chg">
keyword
</ins></a><ins class="diff-chg">
property
definitions
matches
</ins>
any
<del class="diff-old">arbitrary
graph
containing
exactly
</del>
<a class="tref internalDFN" title="subject_definition" href="#dfn-subject_definition">
<ins class="diff-chg">subject
definition
</ins></a><ins class="diff-chg">
having
at
least
</ins>
the
same
<del class="diff-old">information
would
</del>
<ins class="diff-chg">set
of
properties.
</ins></dd><dt><ins class="diff-chg">
Embedding
</ins></dt><dd><ins class="diff-chg">
A
</ins><a class="tref internalDFN" title="frame" href="#dfn-frame"><ins class="diff-chg">
frame
</ins></a><ins class="diff-chg">
including
a
property
which
references
another
</ins><a class="tref internalDFN" title="frame" href="#dfn-frame"><ins class="diff-chg">
frame
</ins></a><ins class="diff-chg">
causes
</ins><a class="tref internalDFN" title="subject_definition" href="#dfn-subject_definition"><ins class="diff-chg">
subject
definitions
</ins></a><ins class="diff-chg">
containing
that
property
and
referencing
either
other
</ins><a class="tref internalDFN" title="subject_definition" href="#dfn-subject_definition"><ins class="diff-chg">
subject
definitions
</ins></a><ins class="diff-chg">
or
</ins><a class="tref internalDFN" title="subject_reference" href="#dfn-subject_reference"><ins class="diff-chg">
subject
references
</ins></a><ins class="diff-chg">
to
embed
</ins><a class="tref internalDFN" title="subject_definition" href="#dfn-subject_definition"><ins class="diff-chg">
subject
definitions
</ins></a><ins class="diff-chg">
matching
the
embed
</ins><a class="tref internalDFN" title="frame" href="#dfn-frame"><ins class="diff-chg">
frame
</ins></a><ins class="diff-chg">
to
</ins>
be
<del class="diff-old">normalized
</del>
<ins class="diff-chg">defined
within
that
property.
</ins><a class="tref internalDFN" title="subject_reference" href="#dfn-subject_reference"><ins class="diff-chg">
Subject
references
</ins></a><ins class="diff-chg">
that
don't
match
the
embed
</ins><a class="tref internalDFN" title="frame" href="#dfn-frame"><ins class="diff-chg">
frame
</ins></a><ins class="diff-chg">
are
dropped.
</ins></dd></dl><p><ins class="diff-chg">
The
[
</ins><cite><a class="bibref" rel="biblioentry" href="#bib-JSON-LD-API"><ins class="diff-chg">
JSON-LD-API
</ins></a></cite><ins class="diff-chg">
]
describes
other
flags
and
</ins><a class="tref internalDFN" title="keyword" href="#dfn-keyword"><ins class="diff-chg">
keywords
</ins></a><ins class="diff-chg">
that
are
used
</ins>
to
<del class="diff-old">exactly
</del>
<ins class="diff-chg">gain
even
more
control
over
</ins>
the
<del class="diff-old">same
form
shown
above.
</del>
<ins class="diff-chg">framed
output.
</ins>
</p>
</div>
</div>
</div>
<div class="appendix informative section" id="markup-examples">
<h2>
<span class="secno">
A.
</span>
Markup
Examples
</h2>
<p>
<em>
This
section
is
non-normative.
</em>
</p>
<p>
JSON-LD
is
a
specification
for
representing
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>
in
JSON.
A
common
way
of
working
with
Linked
Data
is
through
<dfn title="rdf" id="dfn-rdf">
RDF
</dfn>,
the
Resource
Description
Framework.
RDF
can
be
expressed
using
JSON-LD
by
associating
JSON-LD
concepts
such
as
<code>
@id
</code>
and
<code>
@type
</code>
with
the
equivalent
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
s
in
RDF.
Further
information
about
RDF
may
be
found
in
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-RDF-PRIMER">
RDF-PRIMER
</a>
</cite>
].
</p>
<p>
The
JSON-LD
markup
examples
below
demonstrate
how
JSON-LD
can
be
used
to
express
semantic
data
marked
up
in
other
languages
such
as
Turtle,
RDFa,
Microformats,
and
Microdata.
These
sections
are
merely
provided
as
proof
that
JSON-LD
is
very
flexible
in
what
it
can
express
across
different
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>
approaches.
Details
of
transforming
JSON-LD
into
RDF
are
defined
in
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-JSON-LD-API">
JSON-LD-API
</a>
</cite>
].
</p>
<div id="turtle" class="section">
<h3>
<span class="secno">
A.1
</span>
Turtle
</h3>
<p>
The
following
are
examples
of
representing
<a class="tref internalDFN" title="rdf" href="#dfn-rdf">
RDF
</a>
as
expressed
in
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-TURTLE">
TURTLE
</a>
</cite>
]
into
JSON-LD.
</p>
<div id="prefix-definitions" class="section">
<h4>
<span class="secno">
A.1.1
</span>
Prefix
definitions
</h4>
<p>
The
JSON-LD
context
has
direct
equivalents
for
the
Turtle
<code>
@prefix
</code>
declaration:
</p>
<del class="diff-old">@prefix foaf: &lt;http://xmlns.com/foaf/0.1/&gt; .

&lt;http://manu.sporny.org/i/public&gt; a foaf:Person;
  foaf:name &quot;Manu Sporny&quot;;
</del>
<pre class="example">@prefix foaf: &lt;http://xmlns.com/foaf/0.1/&gt; .
<ins class="diff-chg">&lt;http://manu.sporny.org/i/public&gt; a foaf:Person;
  foaf:name &quot;Manu Sporny&quot;;
</ins>
foaf:homepage
&lt;http://manu.sporny.org/&gt;
.
</pre>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
  },
  &quot;@id&quot;: &quot;http://manu.sporny.org/i/public&quot;,
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Manu Sporny&quot;,
  &quot;foaf:homepage&quot;: { &quot;@id&quot;: &quot;http://manu.sporny.org/&quot; }
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
  },
  &quot;@id&quot;: &quot;http://manu.sporny.org/i/public&quot;,
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Manu Sporny&quot;,
  &quot;foaf:homepage&quot;: { &quot;@id&quot;: &quot;http://manu.sporny.org/&quot; }
</ins>
}
</pre>
<div class="note">
<p>
JSON-LD
has
no
equivalent
for
the
Turtle
<code>
@base
</code>
declaration.
Authors
could,
of
course,
use
a
prefix
definition
to
resolve
<a class="tref internalDFN" title="relative_iri" href="#dfn-relative_iri">
relative
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
s.
For
example,
an
empty
prefix
could
be
used
to
get
a
similar
effect
to
<code>
@base
</code>:
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {

    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
  },
  &quot;@id&quot;: ,
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Manu Sporny&quot;,
  &quot;foaf:homepage&quot;: { &quot;@id&quot;: }
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
</ins>    <span class="diff">&quot;&quot;: &quot;http://manu.sporny.org/&quot;,</span><ins class="diff-chg">
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
  },
  &quot;@id&quot;: <span class="diff">&quot;:i/public&quot;</span>,
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Manu Sporny&quot;,
  &quot;foaf:homepage&quot;: { &quot;@id&quot;: <span class="diff">&quot;:&quot; </span>}
</ins>
}
</pre>
</div>
</div>
<div id="embedding-1" class="section">
<h4>
<span class="secno">
A.1.2
</span>
Embedding
</h4>
<p>
Both
Turtle
and
JSON-LD
allow
embedding
of
objects,
although
Turtle
only
allows
embedding
of
objects
which
use
unlabeled
node
identifiers.
</p>
</div>
<del class="diff-old">@prefix foaf: &lt;http://xmlns.com/foaf/0.1/&gt; .

&lt;http://manu.sporny.org/i/public&gt;
  a foaf:Person;
  foaf:name &quot;Manu Sporny&quot;;
</del>
<pre class="example">@prefix foaf: &lt;http://xmlns.com/foaf/0.1/&gt; .
<ins class="diff-chg">&lt;http://manu.sporny.org/i/public&gt;
  a foaf:Person;
  foaf:name &quot;Manu Sporny&quot;;
</ins>
foaf:knows
[
a
foaf:Person;
foaf:name
&quot;Gregg
Kellogg&quot;
]
.
</pre>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
  },
  &quot;@id&quot;: &quot;http://manu.sporny.org/i/public&quot;,
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Manu Sporny&quot;,
  &quot;foaf:knows&quot;:
  {
    &quot;@type&quot;: &quot;foaf:Person&quot;,
    &quot;foaf:name&quot;: &quot;Gregg Kellogg&quot;
  }
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
  },
  &quot;@id&quot;: &quot;http://manu.sporny.org/i/public&quot;,
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Manu Sporny&quot;,
  &quot;foaf:knows&quot;:
  {
    &quot;@type&quot;: &quot;foaf:Person&quot;,
    &quot;foaf:name&quot;: &quot;Gregg Kellogg&quot;
  }
</ins>
}
</pre>
<div id="lists" class="section">
<h4>
<span class="secno">
A.1.3
</span>
Lists
</h4>
<p>
Both
JSON-LD
and
Turtle
can
represent
sequential
lists
of
values.
</p>
<del class="diff-old">@prefix foaf: &lt;http://xmlns.com/foaf/0.1/&gt; .

&lt;http://example.org/people#joebob&gt; a foaf:Person;
  foaf:name &quot;Joe Bob&quot;;
</del>
<pre class="example">@prefix foaf: &lt;http://xmlns.com/foaf/0.1/&gt; .
<ins class="diff-chg">&lt;http://example.org/people#joebob&gt; a foaf:Person;
  foaf:name &quot;Joe Bob&quot;;
</ins>
foaf:nick
(
&quot;joe&quot;
&quot;bob&quot;
&quot;jaybee&quot;
)
.
</pre>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
  },
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Joe Bob&quot;,
  &quot;foaf:nick&quot;:
  {
    &quot;@list&quot;: [ &quot;joe&quot;, &quot;bob&quot;, &quot;jaybe&quot; ]
  }
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
  },
  &quot;@id&quot;: &quot;http://example.org/people#joebob&quot;,
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Joe Bob&quot;,
  &quot;foaf:nick&quot;:
  {
    &quot;@list&quot;: [ &quot;joe&quot;, &quot;bob&quot;, &quot;jaybe&quot; ]
  }
</ins>
}
</pre>
</div>
</div>
<div id="rdfa" class="section">
<h3>
<span class="secno">
A.2
</span>
RDFa
</h3>
<p>
The
following
example
describes
three
people
with
their
respective
names
and
homepages.
</p>
<del class="diff-old">&gt;
   &lt;ul&gt;
      &lt;li &gt;
        &lt;a &gt;Bob&lt;/a&gt;
      &lt;/li&gt;
      &lt;li &gt;
        &lt;a &gt;Eve&lt;/a&gt;
      &lt;/li&gt;
      &lt;li &gt;
        &lt;a &gt;Manu&lt;/a&gt;
      &lt;/li&gt;
   &lt;/ul&gt;
</del>
<pre class="example">&lt;div <span class="diff">prefix=&quot;foaf: http://xmlns.com/foaf/0.1/&quot;</span>&gt;
<ins class="diff-chg">   &lt;ul&gt;
      &lt;li <span class="diff">typeof=&quot;foaf:Person&quot;</span>&gt;
        &lt;a <span class="diff">rel=&quot;foaf:homepage&quot; href=&quot;http://example.com/bob/&quot; property=&quot;foaf:name&quot; </span>&gt;Bob&lt;/a&gt;
      &lt;/li&gt;
      &lt;li <span class="diff">typeof=&quot;foaf:Person&quot;</span>&gt;
        &lt;a <span class="diff">rel=&quot;foaf:homepage&quot; href=&quot;http://example.com/eve/&quot; property=&quot;foaf:name&quot; </span>&gt;Eve&lt;/a&gt;
      &lt;/li&gt;
      &lt;li <span class="diff">typeof=&quot;foaf:Person&quot;</span>&gt;
        &lt;a <span class="diff">rel=&quot;foaf:homepage&quot; href=&quot;http://example.com/manu/&quot; property=&quot;foaf:name&quot; </span>&gt;Manu&lt;/a&gt;
      &lt;/li&gt;
   &lt;/ul&gt;
</ins>
&lt;/div&gt;
</pre>
<p>
An
example
JSON-LD
implementation
using
a
single
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
is
described
below.
</p>
<del class="diff-old">The
syntax
to
serialize
multiple
graphs
is
currently
being
discussed
in
Issue
68
.
{
  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
  },
  &quot;@id&quot;:
  [
    {
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;foaf:homepage&quot;: &quot;http://example.com/bob/&quot;,
      &quot;foaf:name&quot;: &quot;Bob&quot;
    },
    {
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;foaf:homepage&quot;: &quot;http://example.com/eve/&quot;,
      &quot;foaf:name&quot;: &quot;Eve&quot;
    },
    {
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;foaf:homepage&quot;: &quot;http://example.com/manu/&quot;,
      &quot;foaf:name&quot;: &quot;Manu&quot;
    }
  ]
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;
  },
  &quot;@graph&quot;:
  [
    {
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;foaf:homepage&quot;: &quot;http://example.com/bob/&quot;,
      &quot;foaf:name&quot;: &quot;Bob&quot;
    },
    {
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;foaf:homepage&quot;: &quot;http://example.com/eve/&quot;,
      &quot;foaf:name&quot;: &quot;Eve&quot;
    },
    {
      &quot;@type&quot;: &quot;foaf:Person&quot;,
      &quot;foaf:homepage&quot;: &quot;http://example.com/manu/&quot;,
      &quot;foaf:name&quot;: &quot;Manu&quot;
    }
  ]
</ins>
}
</pre>
</div>
<div id="microformats" class="section">
<h3>
<span class="secno">
A.3
</span>
Microformats
</h3>
<p>
The
following
example
uses
a
simple
Microformats
hCard
example
to
express
how
the
Microformat
is
represented
in
JSON-LD.
</p>
<del class="diff-old">&lt;div class=&quot;vcard&quot;&gt;
 &lt;a class=&quot;url fn&quot; href=&quot;http://www.markus-lanthaler.com/&quot;&gt;Markus Lanthaler&lt;/a&gt;
</del>
<pre class="example">&lt;div class=&quot;vcard&quot;&gt;
<ins class="diff-chg"> &lt;a class=&quot;url fn&quot; href=&quot;http://www.markus-lanthaler.com/&quot;&gt;Markus Lanthaler&lt;/a&gt;
</ins>
&lt;/div&gt;
</pre>
<p>
The
representation
of
the
hCard
expresses
the
Microformat
terms
in
the
<a class="tref internalDFN" title="context" href="#dfn-context">
context
</a>
and
uses
them
directly
for
the
<code>
url
</code>
and
<code>
fn
</code>
properties.
Also
note
that
the
Microformat
to
JSON-LD
processor
has
generated
the
proper
URL
type
for
<code>
http://tantek.com/
</code>.
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    &quot;vcard&quot;: &quot;http://microformats.org/profile/hcard#vcard&quot;,
    &quot;url&quot;:
    {
      &quot;@id&quot;: &quot;http://microformats.org/profile/hcard#url&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
    &quot;fn&quot;: &quot;http://microformats.org/profile/hcard#fn&quot;
  },
  &quot;@type&quot;: &quot;vcard&quot;,
  &quot;url&quot;: &quot;http://www.markus-lanthaler.com/&quot;,
  &quot;fn&quot;: &quot;Markus Lanthaler&quot;
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
    &quot;vcard&quot;: &quot;http://microformats.org/profile/hcard#vcard&quot;,
    &quot;url&quot;:
    {
      &quot;@id&quot;: &quot;http://microformats.org/profile/hcard#url&quot;,
      &quot;@type&quot;: &quot;@id&quot;
    },
    &quot;fn&quot;: &quot;http://microformats.org/profile/hcard#fn&quot;
  },
  &quot;@type&quot;: &quot;vcard&quot;,
  &quot;url&quot;: &quot;http://www.markus-lanthaler.com/&quot;,
  &quot;fn&quot;: &quot;Markus Lanthaler&quot;
</ins>
}
</pre>
</div>
<div id="microdata" class="section">
<h3>
<span class="secno">
A.4
</span>
Microdata
</h3>
<p>
The
microdata
example
below
expresses
book
information
as
a
microdata
Work
item.
</p>
<del class="diff-old">&lt;dl itemscope
    itemtype=&quot;http://purl.org/vocab/frbr/core#Work&quot;
    itemid=&quot;http://purl.oreilly.com/works/45U8QJGZSQKDH8N&quot;&gt;
 &lt;dt&gt;Title&lt;/dt&gt;
 &lt;dd&gt;&lt;cite itemprop=&quot;http://purl.org/dc/terms/title&quot;&gt;Just a Geek&lt;/cite&gt;&lt;/dd&gt;
 &lt;dt&gt;By&lt;/dt&gt;
 &lt;dd&gt;&lt;span itemprop=&quot;http://purl.org/dc/terms/creator&quot;&gt;Wil Wheaton&lt;/span&gt;&lt;/dd&gt;
 &lt;dt&gt;Format&lt;/dt&gt;
 &lt;dd itemprop=&quot;http://purl.org/vocab/frbr/core#realization&quot;
     itemscope
     itemtype=&quot;http://purl.org/vocab/frbr/core#Expression&quot;
     itemid=&quot;http://purl.oreilly.com/products/9780596007683.BOOK&quot;&gt;
  &lt;link itemprop=&quot;http://purl.org/dc/terms/type&quot; href=&quot;http://purl.oreilly.com/product-types/BOOK&quot;&gt;
  Print
 &lt;/dd&gt;
 &lt;dd itemprop=&quot;http://purl.org/vocab/frbr/core#realization&quot;
     itemscope
     itemtype=&quot;http://purl.org/vocab/frbr/core#Expression&quot;
     itemid=&quot;http://purl.oreilly.com/products/9780596802189.EBOOK&quot;&gt;
  &lt;link itemprop=&quot;http://purl.org/dc/terms/type&quot; href=&quot;http://purl.oreilly.com/product-types/EBOOK&quot;&gt;
  Ebook
 &lt;/dd&gt;
</del>
<pre class="example">&lt;dl itemscope
<ins class="diff-chg">    itemtype=&quot;http://purl.org/vocab/frbr/core#Work&quot;
    itemid=&quot;http://purl.oreilly.com/works/45U8QJGZSQKDH8N&quot;&gt;
 &lt;dt&gt;Title&lt;/dt&gt;
 &lt;dd&gt;&lt;cite itemprop=&quot;http://purl.org/dc/terms/title&quot;&gt;Just a Geek&lt;/cite&gt;&lt;/dd&gt;
 &lt;dt&gt;By&lt;/dt&gt;
 &lt;dd&gt;&lt;span itemprop=&quot;http://purl.org/dc/terms/creator&quot;&gt;Wil Wheaton&lt;/span&gt;&lt;/dd&gt;
 &lt;dt&gt;Format&lt;/dt&gt;
 &lt;dd itemprop=&quot;http://purl.org/vocab/frbr/core#realization&quot;
     itemscope
     itemtype=&quot;http://purl.org/vocab/frbr/core#Expression&quot;
     itemid=&quot;http://purl.oreilly.com/products/9780596007683.BOOK&quot;&gt;
  &lt;link itemprop=&quot;http://purl.org/dc/terms/type&quot; href=&quot;http://purl.oreilly.com/product-types/BOOK&quot;&gt;
  Print
 &lt;/dd&gt;
 &lt;dd itemprop=&quot;http://purl.org/vocab/frbr/core#realization&quot;
     itemscope
     itemtype=&quot;http://purl.org/vocab/frbr/core#Expression&quot;
     itemid=&quot;http://purl.oreilly.com/products/9780596802189.EBOOK&quot;&gt;
  &lt;link itemprop=&quot;http://purl.org/dc/terms/type&quot; href=&quot;http://purl.oreilly.com/product-types/EBOOK&quot;&gt;
  Ebook
 &lt;/dd&gt;
</ins>
&lt;/dl&gt;
</pre>
<p>
Note
that
the
JSON-LD
representation
of
the
Microdata
information
stays
true
to
the
desires
of
the
Microdata
community
to
avoid
contexts
and
instead
refer
to
items
by
their
full
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
</p>
<del class="diff-old">[
  {
    &quot;@id&quot;: &quot;http://purl.oreilly.com/works/45U8QJGZSQKDH8N&quot;,
    &quot;@type&quot;: &quot;http://purl.org/vocab/frbr/core#Work&quot;,
    &quot;http://purl.org/dc/terms/title&quot;: &quot;Just a Geek&quot;,
    &quot;http://purl.org/dc/terms/creator&quot;: &quot;Whil Wheaton&quot;,
    &quot;http://purl.org/vocab/frbr/core#realization&quot;:
    [
      &quot;http://purl.oreilly.com/products/9780596007683.BOOK&quot;,
      &quot;http://purl.oreilly.com/products/9780596802189.EBOOK&quot;
    ]
  },
  {
    &quot;@id&quot;: &quot;http://purl.oreilly.com/products/9780596007683.BOOK&quot;,
    &quot;@type&quot;: &quot;http://purl.org/vocab/frbr/core#Expression&quot;,
    &quot;http://purl.org/dc/terms/type&quot;: &quot;http://purl.oreilly.com/product-types/BOOK&quot;
  },
  {
    &quot;@id&quot;: &quot;http://purl.oreilly.com/products/9780596802189.EBOOK&quot;,
    &quot;@type&quot;: &quot;http://purl.org/vocab/frbr/core#Expression&quot;,
    &quot;http://purl.org/dc/terms/type&quot;: &quot;http://purl.oreilly.com/product-types/EBOOK&quot;
  }
</del>
<pre class="example">[
<ins class="diff-chg">  {
    &quot;@id&quot;: &quot;http://purl.oreilly.com/works/45U8QJGZSQKDH8N&quot;,
    &quot;@type&quot;: &quot;http://purl.org/vocab/frbr/core#Work&quot;,
    &quot;http://purl.org/dc/terms/title&quot;: &quot;Just a Geek&quot;,
    &quot;http://purl.org/dc/terms/creator&quot;: &quot;Whil Wheaton&quot;,
    &quot;http://purl.org/vocab/frbr/core#realization&quot;:
    [
      &quot;http://purl.oreilly.com/products/9780596007683.BOOK&quot;,
      &quot;http://purl.oreilly.com/products/9780596802189.EBOOK&quot;
    ]
  },
  {
    &quot;@id&quot;: &quot;http://purl.oreilly.com/products/9780596007683.BOOK&quot;,
    &quot;@type&quot;: &quot;http://purl.org/vocab/frbr/core#Expression&quot;,
    &quot;http://purl.org/dc/terms/type&quot;: &quot;http://purl.oreilly.com/product-types/BOOK&quot;
  },
  {
    &quot;@id&quot;: &quot;http://purl.oreilly.com/products/9780596802189.EBOOK&quot;,
    &quot;@type&quot;: &quot;http://purl.org/vocab/frbr/core#Expression&quot;,
    &quot;http://purl.org/dc/terms/type&quot;: &quot;http://purl.oreilly.com/product-types/EBOOK&quot;
  }
</ins>
]
</pre>
</div>
</div>
<div class="appendix section" id="linked-data">
<h2>
<span class="secno">
B.
</span>
Linked
Data
</h2>
<p>
The
following
definition
for
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>
is
the
one
that
will
be
used
for
this
specification.
</p>
<ol>
<li>
<dfn title="linked_data" id="dfn-linked_data">
Linked
Data
</dfn>
is
a
set
of
documents,
each
containing
a
representation
of
a
linked
data
graph.
</li>
<li>
A
<dfn title="linked_data_graph" id="dfn-linked_data_graph">
linked
data
graph
</dfn>
is
an
unordered
labeled
directed
graph,
where
nodes
are
<a class="tref internalDFN" title="subject" href="#dfn-subject">
subject
</a>
s
or
<a class="tref internalDFN" title="object" href="#dfn-object">
object
</a>
s,
and
edges
are
properties.
</li>
<li>
A
<dfn title="subject" id="dfn-subject">
subject
</dfn>
is
any
node
in
a
<a class="tref internalDFN" title="linked_data_graph" href="#dfn-linked_data_graph">
linked
data
graph
</a>
with
at
least
one
outgoing
edge.
</li>
<li>
A
<a class="tref internalDFN" title="subject" href="#dfn-subject">
subject
</a>
<em class="rfc2119" title="should">
should
</em>
be
labeled
with
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
(an
Internationalized
Resource
Identifier
as
described
in
[
<cite>
<a class="bibref" rel="biblioentry" href="#bib-RFC3987">
RFC3987
</a>
</cite>
]).
</li>
<li>
An
<dfn title="object" id="dfn-object">
object
</dfn>
is
a
node
in
a
<a class="tref internalDFN" title="linked_data_graph" href="#dfn-linked_data_graph">
linked
data
graph
</a>
with
at
least
one
incoming
edge.
</li>
<li>
An
<a class="tref internalDFN" title="object" href="#dfn-object">
object
</a>
<em class="rfc2119" title="may">
may
</em>
be
labeled
with
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
</li>
<li>
A
node
<em class="rfc2119" title="may">
may
</em>
be
a
<a class="tref internalDFN" title="subject" href="#dfn-subject">
subject
</a>
and
<a class="tref internalDFN" title="object" href="#dfn-object">
object
</a>
at
the
same
time.
</li>
<li>
A
<dfn title="property" id="dfn-property">
property
</dfn>
is
an
edge
of
the
<a class="tref internalDFN" title="linked_data_graph" href="#dfn-linked_data_graph">
linked
data
graph
</a>.
</li>
<li>
A
<a class="tref internalDFN" title="property" href="#dfn-property">
property
</a>
<em class="rfc2119" title="should">
should
</em>
be
labeled
with
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>.
</li>
<li>
An
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
that
is
a
label
in
a
<a class="tref internalDFN" title="linked_data_graph" href="#dfn-linked_data_graph">
linked
data
graph
</a>
<em class="rfc2119" title="should">
should
</em>
be
dereferencable
to
a
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>
document
describing
the
labeled
<a class="tref internalDFN" title="subject" href="#dfn-subject">
subject
</a>,
<a class="tref internalDFN" title="object" href="#dfn-object">
object
</a>
or
<a class="tref internalDFN" title="property" href="#dfn-property">
property
</a>.
</li>
<li>
A
<dfn title="value" id="dfn-value">
value
</dfn>
is
an
<a class="tref internalDFN" title="object" href="#dfn-object">
object
</a>
with
a
label
that
is
not
an
<a class="tref internalDFN" title="iri" href="#dfn-iri">
<abbr title="Internationalized Resource Identifier">
IRI
</abbr>
</a>
</li>
</ol>
<p>
Note
that
the
definition
for
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>
above
is
silent
on
the
topic
of
unlabeled
nodes.
Unlabeled
nodes
are
not
considered
<a class="tref internalDFN" title="linked_data" href="#dfn-linked_data">
Linked
Data
</a>.
However,
this
specification
allows
for
the
expression
of
unlabled
nodes,
as
most
graph-based
data
sets
on
the
Web
contain
a
number
of
associated
nodes
that
are
not
named
and
thus
are
not
directly
de-referenceable.
</p>
</div>
<div class="appendix informative section" id="mashing-up-vocabularies">
<h2>
<span class="secno">
C.
</span>
Mashing
Up
Vocabularies
</h2>
<p>
<em>
This
section
is
non-normative.
</em>
</p>
<p>
Developers
benefit
by
being
able
to
mash
other
<a class="tref internalDFN" title="vocabulary" href="#dfn-vocabulary">
vocabularies
</a>
into
their
JSON-LD
markup.
There
are
over
200
<a class="tref internalDFN" title="vocabulary" href="#dfn-vocabulary">
vocabularies
</a>
that
are
available
for
use
on
the
Web
today.
Some
of
these
<a class="tref internalDFN" title="vocabulary" href="#dfn-vocabulary">
vocabularies
</a>
include:
</p>
<ul>
<li>
RDF
-
for
describing
information
about
objects
and
concepts
on
the
Web.
</li>
<li>
RDFS
-
for
expressing
things
like
labels
and
comments.
</li>
<li>
XSD
-
for
specifying
basic
types
like
strings,
integers,
dates
and
times.
</li>
<li>
Dublin
Core
-
for
describing
creative
works.
</li>
<li>
FOAF
-
for
describing
social
networks.
</li>
<li>
Calendar
-
for
specifying
events.
</li>
<li>
SIOC
-
for
describing
discussions
on
blogs
and
websites.
</li>
<li>
CCrel
-
for
describing
Creative
Commons
and
other
types
of
licenses.
</li>
<li>
GEO
-
for
describing
geographic
location.
</li>
<li>
VCard
-
for
describing
organizations
and
people.
</li>
<li>
DOAP
-
for
describing
projects.
</li>
</ul>
<p>
You
can
use
these
<a class="tref internalDFN" title="vocabulary" href="#dfn-vocabulary">
vocabularies
</a>
in
combination,
like
so:
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;,
    &quot;sioc&quot;: &quot;http://rdfs.org/sioc/ns#&quot;,
    &quot;rdfs&quot;: &quot;http://www.w3.org/2000/01/rdf-schema#&quot;
  },
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Manu Sporny&quot;,
  &quot;foaf:homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;sioc:avatar&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;,
  &quot;rdfs:comment&quot;: &quot;Likes puppies, unicorns and rainbows.&quot;
</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;,<span class="diff">
    &quot;sioc&quot;: &quot;http://rdfs.org/sioc/ns#&quot;,
    &quot;rdfs&quot;: &quot;http://www.w3.org/2000/01/rdf-schema#&quot;</span>
  },
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Manu Sporny&quot;,
  &quot;foaf:homepage&quot;: &quot;http://manu.sporny.org/&quot;,<span class="diff">
  &quot;sioc:avatar&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;,
  &quot;rdfs:comment&quot;: &quot;Likes puppies, unicorns and rainbows.&quot;</span>
</ins>
}
</pre>
<p>
Developers
can
also
specify
their
own
<a class="tref internalDFN" title="vocabulary" href="#dfn-vocabulary">
vocabulary
</a>
documents
by
modifying
the
<a class="tref internalDFN" title="active_context" href="#dfn-active_context">
active
context
</a>
in-line
using
the
<code>
@context
</code>
keyword,
like
so:
</p>
<del class="diff-old">{
  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;,
    &quot;sioc&quot;: &quot;http://rdfs.org/sioc/ns#&quot;,
    &quot;rdfs&quot;: &quot;http://www.w3.org/2000/01/rdf-schema#&quot;,

  },
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Manu Sporny&quot;,
  &quot;foaf:homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;sioc:avatar&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;,
  &quot;rdfs:comment&quot;: &quot;Likes puppies, unicorns and rainbows.&quot;

</del>
<pre class="example">{
<ins class="diff-chg">  &quot;@context&quot;:
  {
    &quot;foaf&quot;: &quot;http://xmlns.com/foaf/0.1/&quot;,
    &quot;sioc&quot;: &quot;http://rdfs.org/sioc/ns#&quot;,
    &quot;rdfs&quot;: &quot;http://www.w3.org/2000/01/rdf-schema#&quot;,
</ins>    <span class="diff">&quot;myvocab&quot;: &quot;http://example.org/myvocab#&quot;</span><ins class="diff-chg">
  },
  &quot;@type&quot;: &quot;foaf:Person&quot;,
  &quot;foaf:name&quot;: &quot;Manu Sporny&quot;,
  &quot;foaf:homepage&quot;: &quot;http://manu.sporny.org/&quot;,
  &quot;sioc:avatar&quot;: &quot;http://twitter.com/account/profile_image/manusporny&quot;,
  &quot;rdfs:comment&quot;: &quot;Likes puppies, unicorns and rainbows.&quot;
</ins>  <span class="diff">&quot;myvocab:personality&quot;: &quot;friendly&quot;</span>
}
</pre>
</div>
<div class="appendix informative section" id="iana-considerations">
<h2>
<span class="secno">
D.
</span>
IANA
Considerations
</h2>
<p>
<em>
This
section
is
non-normative.
</em>
</p>
<p>
This
section
is
included
merely
for
standards
community
review
and
will
be
submitted
to
the
Internet
Engineering
Steering
Group
if
this
specification
becomes
a
W3C
Recommendation.
</p>
<dl>
<dt>
Type
name:
</dt>
<dd>
application
</dd>
<dt>
Subtype
name:
</dt>
<dd>
ld+json
</dd>
<dt>
Required
parameters:
</dt>
<dd>
None
</dd>
<dt>
Optional
parameters:
</dt>
<dd>
<dl>
<dt>
<code>
form
</code>
</dt>
<dd>
Determines
the
serialization
form
for
the
JSON-LD
document.
<del class="diff-old">Valid
values
are
</del>
<ins class="diff-chg">The
only
valid
value
at
the
moment
is
</ins>
<code>
expanded
<del class="diff-old">and
normalized
</del>
</code>.
If
no
form
is
specified
in
an
HTTP
request
header
to
an
HTTP
server,
the
server
<em class="rfc2119" title="may">
may
</em>
choose
any
form.
If
no
form
is
specified
<del class="diff-old">for
</del>
<ins class="diff-chg">in
</ins>
an
HTTP
<del class="diff-old">client,
</del>
<ins class="diff-chg">response,
</ins>
the
form
<em class="rfc2119" title="must not">
must
not
</em>
be
assumed
to
take
any
particular
form.
</dd>
</dl>
</dd>
<dt>
Encoding
considerations:
</dt>
<dd>
The
same
as
the
<code>
application/json
</code>
MIME
media
type.
</dd>
<dt>
Security
considerations:
</dt>
<dd>
Since
JSON-LD
is
intended
to
be
a
pure
data
exchange
format
for
directed
graphs,
the
serialization
<em class="rfc2119" title="should not">
should
not
</em>
be
passed
through
a
code
execution
mechanism
such
as
JavaScript's
<code>
eval()
</code>
function.
It
is
<em class="rfc2119" title="recommended">
recommended
</em>
that
a
conforming
parser
does
not
attempt
to
directly
evaluate
the
JSON-LD
serialization
and
instead
purely
parse
the
input
into
a
language-native
data
structure.
</dd>
<dt>
Interoperability
considerations:
</dt>
<dd>
Not
Applicable
</dd>
<dt>
Published
specification:
</dt>
<dd>
The
<a href="http://json-ld.org/spec/latest/">
JSON-LD
</a>
specification.
</dd>
<dt>
Applications
that
use
this
media
type:
</dt>
<dd>
Any
programming
environment
that
requires
the
exchange
of
directed
graphs.
Implementations
of
JSON-LD
have
been
created
for
JavaScript,
Python,
Ruby,
PHP
and
C++.
</dd>
<dt>
Additional
information:
</dt>
<dd>
<dl>
<dt>
Magic
number(s):
</dt>
<dd>
Not
Applicable
</dd>
<dt>
File
extension(s):
</dt>
<dd>.jsonld
</dd>
<dt>
Macintosh
file
type
code(s):
</dt>
<dd>
TEXT
</dd>
</dl>
</dd>
<dt>
Person
&amp;
email
address
to
contact
for
further
information:
</dt>
<dd>
Manu
Sporny
&lt;msporny@digitalbazaar.com&gt;
</dd>
<dt>
Intended
usage:
</dt>
<dd>
Common
</dd>
<dt>
Restrictions
on
usage:
</dt>
<dd>
None
</dd>
<dt>
Author(s):
</dt>
<dd>
Manu
Sporny,
Gregg
Kellogg,
Markus
Lanthaler,
Dave
Longley
</dd>
<dt>
Change
controller:
</dt>
<dd>
W3C
</dd>
</dl>
</div>
<div class="appendix informative section" id="acknowledgements">
<h2>
<span class="secno">
E.
</span>
Acknowledgements
</h2>
<p>
<em>
This
section
is
non-normative.
</em>
</p>
<p>
The
editors
would
like
to
thank
Mark
Birbeck,
who
provided
a
great
deal
of
the
initial
push
behind
the
JSON-LD
work
via
his
work
on
RDFj,
Dave
Longley,
Dave
Lehn
and
Mike
Johnson
who
reviewed,
provided
feedback,
and
performed
several
implementations
of
the
specification,
and
Ian
Davis,
who
created
RDF/JSON.
Thanks
also
to
Nathan
Rixham,
Bradley
P.
Allen,
Kingsley
Idehen,
Glenn
McDonald,
Alexandre
Passant,
Danny
Ayers,
Ted
Thibodeau
Jr.,
Olivier
Grisel,
Niklas
Lindström,
Markus
Lanthaler,
and
Richard
Cyganiak
for
their
input
on
the
specification.
</p>
</div>
<div id="references" class="appendix section">
<h2>
<span class="secno">
F.
</span>
References
</h2>
<div id="normative-references" class="section">
<h3>
<span class="secno">
F.1
</span>
Normative
references
</h3>
<dl class="bibliography">
<dt id="bib-BCP47">
[BCP47]
</dt>
<dd>
A.
Phillips,
M.
Davis.
<del class="diff-old">&lt;a href="http://tools.ietf.org/rfc/bcp/
</del>
<a href="http://tools.ietf.org/rfc/bcp/bcp47.txt">
<cite>
<ins class="diff-chg">Tags
for
Identifying
Languages
</ins></cite></a><ins class="diff-chg">
September
2009.
IETF
Best
Current
Practice.
URL:
</ins><a href="http://tools.ietf.org/rfc/bcp/bcp47.txt"><ins class="diff-chg">
http://tools.ietf.org/rfc/bcp/bcp47.txt
</ins></a></dd><dt id="bib-JSON-LD-API"><ins class="diff-chg">
[JSON-LD-API]
</ins></dt><dd><ins class="diff-chg">
Manu
Sporny,
Gregg
Kellogg,
Dave
Longley,
Markus
Lanthaler,
Eds.
</ins><cite><a href="http://json-ld.org/spec/latest/json-ld-api/"><ins class="diff-chg">
JSON-LD
API
</ins></a></cite><ins class="diff-chg">
Latest.
W3C
Editor's
Draft.
URL:
</ins><a href="http://json-ld.org/spec/latest/json-ld-api/"><ins class="diff-chg">
http://json-ld.org/spec/latest/json-ld-api/
</ins></a></dd><dt id="bib-RFC3987"><ins class="diff-chg">
[RFC3987]
</ins></dt><dd><ins class="diff-chg">
M.
Dürst;
M.
Suignard.
</ins><a href="http://www.ietf.org/rfc/rfc3987.txt"><cite><ins class="diff-chg">
Internationalized
Resource
Identifiers
(IRIs).
</ins></cite></a><ins class="diff-chg">
January
2005.
Internet
RFC
3987.
URL:
</ins><a href="http://www.ietf.org/rfc/rfc3987.txt"><ins class="diff-chg">
http://www.ietf.org/rfc/rfc3987.txt
</ins></a></dd><dt id="bib-RFC4627"><ins class="diff-chg">
[RFC4627]
</ins></dt><dd><ins class="diff-chg">
D.
Crockford.
</ins><a href="http://www.ietf.org/rfc/rfc4627.txt"><cite><ins class="diff-chg">
The
application/json
Media
Type
for
JavaScript
Object
Notation
(JSON)
</ins></cite></a><ins class="diff-chg">
July
2006.
Internet
RFC
4627.
URL:
</ins><a href="http://www.ietf.org/rfc/rfc4627.txt"><ins class="diff-chg">
http://www.ietf.org/rfc/rfc4627.txt
</ins></a></dd><dt id="bib-RFC5988"><ins class="diff-chg">
[RFC5988]
</ins></dt><dd><ins class="diff-chg">
M.
Nottingham.
</ins><a href="http://tools.ietf.org/rfc/rfc5988"><cite><ins class="diff-chg">
Web
Linking
</ins></cite></a><ins class="diff-chg">
October
2010.
IETF
Standard.
URL:
</ins><a href="http://tools.ietf.org/rfc/rfc5988.txt"><ins class="diff-chg">
http://tools.ietf.org/rfc/rfc5988.txt
</ins></a></dd><dt id="bib-WEBIDL"><ins class="diff-chg">
[WEBIDL]
</ins></dt><dd><ins class="diff-chg">
Cameron
McCormack.
</ins><a href="http://www.w3.org/TR/2011/WD-WebIDL-20110927/"><cite><ins class="diff-chg">
Web
IDL.
</ins></cite></a><ins class="diff-chg">
27
September
2011.
W3C
Working
Draft.
(Work
in
progress.)
URL:
</ins><a href="http://www.w3.org/TR/2011/WD

